Question

please help......
((2z-8)/(z^2-4))/((z^2+6z+8)/(z-4))
simplify completly..... show work

Answer 1

do you know how to do this?

Answer 2

First Flip bottom fraction and Multiply
Then factor and things will cancel
\[2z-8 = 2(z-4)\]
\[z^{2}-4 = (z+2)(z-2)\]
\[z^{2}+6z+8=(z+4)(z+2)\]

Answer 3

wow i forgot that the things cancelled.... okay what did you get for your answer?

Answer 4

im not sure how you did that can you show me?

Answer 5

\[=\frac{2(z-4)(z-4)}{(z+2)(z+2)(z-2)(z+4)}\]
hmm maybe they dont cancel in this case..haha

Answer 6

yea and i think you factored wrong.....

Answer 7

wait how did you factor that?

Answer 8

no everything is factored correctly

Answer 9

which one

Answer 10

how did you do it then? i got something completly different but i thrust what you got....

Answer 11

are you sure its division and not multiplying the 2 fractions ??

Answer 12

you flip the second one and change to multi.

Answer 13

correct

Answer 14

and then can you show me what you did im completly lost

Answer 15

oh for the factoring part.
well for 2z -8 i just pulled out a 2 from each term
2(z-4) = 2z - 8

Answer 16

ok

Answer 17

For z^2 - 4,
find factors of -4 that add up to 0 since there is no "z" term
-2*2 = -4 and -2+2=0
(z-2)(z+2)

Answer 18

wow thats sooo much easier now thanks :)
can you help me with a couple more?

Answer 19

z^2 +6z +8
same thing, look for factors of 8 that add up to 6
4*2 =8 and 4+2 =6
(z+4)(z+2)

Answer 20

ok

Answer 21

okay.......
((4)/(2x+1))-((3)/(2x))=

Answer 22

can you show me step by step please?

Answer 23

adding/subtracting fractions you need to get common denominator
2x+1 cannot be factored
2x cannot be factored
common denominator is 2x(2x+1)

just like adding 1/2 + 1/3, common denominator is 2*3=6

Answer 24

now change numerators
\[\frac{4}{2x+1} = \frac{(2x)(4)}{2x(2x+1)}\]
\[\frac{3}{2x} = \frac{3(2x+1)}{2x(2x+1)}\]
combine into 1 fraction
\[\frac{(2x)(4) - 3(2x+1)}{2x(2x+1)}\]

Answer 25

ok

Answer 26

multiply and add like terms on top
\[\frac{8x -6x -3}{2x(2x+1)} = \frac{2x-3}{2x(2x+1)}\]

Answer 27

can you help me with this one?
((m+5)/(2m^2-2))+((3)/(1-m))+((5)/(2m+2))

Answer 28

factor all the denominators
2m^2 -2 = 2(m-1)(m+1)
1-m = -(m-1)
2m+2 = 2(m+1)
common denominator will include everything w/out repeats
-2(m-1)(m+1)

Answer 29

okay i can do it from there can you help me with this one?
((n+1)-(2/n))/((n+4)+(4/n))

Answer 30

\[=\frac{-(m+5)+(2(m+1))(3) + (-(m-1))(5)}{-2(m+1)(m-1)}\]

Answer 31

can you help me with this one? please????
((n+1)-(2/n))/((n+4)+(4/n))

Answer 32

ok combine fractions on top and bottom, then flip and multiply

Answer 33

common denominator will just be n

Answer 34

ok

Answer 35

answer should be (n-1)/(n+2)

Answer 36

yup that what i got are you good with summation notation and geometric means/sequences?

Answer 37

sure

Answer 38

okay.... wellthe question is...
insert four geometirc means between -7 and -224

Answer 39

hmm dont understand?

Answer 40

nevermind i figured that one out......

Answer 41

what about....

Answer 42

\[\sum_{n=1}^{50}(1/4)(n+2)\]

Answer 43

\[=\frac{1}{4}\sum_{n=1}^{50}n+2 = \frac{1}{4}(\sum_{n=1}^{50}n +\sum_{n=1}^{50}2)\]

Answer 44

im stuck on this one..
which term of the geometric sequence 243, -81, 27, . . . is (-1/9)?

Answer 45

8 th term

Answer 46

how did you figure that out?

Answer 47

haha tried proving it using geometric sequence formula but got stuck when taking log
anyway just continue the sequence of dividing by 3 and flipping the sign

Answer 48

o so you flip the sign every other time?

could you help me with this one?

there are seven houses; in each are seven cats. each cat kills seven mice. each mouse would hvae eaten seven ears of wheat. each ear of wheat prodece seven measures of grain. how much grain is saved?

i got 16807 grains saved

Answer 49

correct
7^3 mice
7^4 ears
7^5 grain

Answer 50

ok that equals 16807 which is what i got:)

Answer 51

okay change the repeating decimal .25 (sopposto have the bar above the 25) to an equivlant common fraction

Answer 52

?? why do you need to know that
some fraction close to proportional of 1/4

Answer 53

i dontk know its on my homework though ydo you know what it'd be?

Answer 54

haha i just guessed and put it in my calculator
25/99

Answer 55

wow your good.... do you know how i would show that? just say guess and check? we turn this in for a grade thats why im asking

Answer 56

actually any n/99 = .nnnnnn

Answer 57

in a certain credit union, money left on deposit for one year earns 4% intrest at the end ot the year. if you invested $100 at the beginning of each year in this credit union and did NOT withdraw the intrest due at the end of the year, how much would you hvae on deposit at the end of the tenth year?

Answer 58

=100(1.04 + 1.04^2+... +1.04^10)
need sum of geometric sequence
sum = a(1-r^n)/(1-r)
sum = 1.04(1-1.04^10)/(1-1.04)

Answer 59

i get 1248.64

Answer 60

so when you get your answer are you sopposto multiply it by 100?

Answer 61

yes

Answer 62

okay just stay right there i have a couple more i just have to go and get another pencil mine just broke

Answer 63

ok im back i dont know what formula you used

Answer 64

for finding sum of geometric sequence

Answer 65

yea but can you tell me it with all of the variable in it please? i need to look and see if i have that one

Answer 66

\[s _{n} = \frac{a _{1}(1-r ^{n})}{1-r}\]

Answer 67

i only have
SofN=(Asub1-Asub1R^n)/(1-R)
and...
SofN=(Asub1-AsubnR)/(1-R)
sooo.. which one should i use, and what numbers?

Answer 68

ues the first one, only difference is mine has factored out the a1 on top

Answer 69

a1 = first term
r = common ratio

Answer 70

ummmm... i should get the same answer right?
i think im doing someting wrong im getting 1200.610712

Answer 71

1-(1.04)^10 = -.4802
1.04(-.4802) = -.49945
-.49945/(1-1.04) = 12.48635

Answer 72

wait shouldnt it be.....

(100-100(1.04)^10)/(1-1.04)

Answer 73

no im leaving the 100 on outside of sequence
then we multiply the sum by 100

Answer 74

but when i do it shouldnt i be getting the same thing? and i dont understand how your doing it

Answer 75

ok if you include the 100 then sequence will look like this
=100(1.04) + 100(1.04^2) +...+100(1.04^10)
a1 = 100(1.04)
r = 1.04
sn = 100(1.04)(1-1.04^10)/(1-1.04)

Answer 76

but my equation is Sn=(A1-A1R^n)/(1-R)

Answer 77

same thing
factor out the A1

Answer 78

can you do it my way when you factor out the A1 it confuses me

Answer 79

....^because when you factor....

Answer 80

ok
Sn = 100(1.04) -100(1.04)(1.04^10) / (1-1.04)

Answer 81

ok ...
a ball which rolls off a penthouse terrace falls 16 feet the first second, 48 feet the next second, and 80 feet the third second. if it continues to fall in this mannor, how far does it fall in the seventh second?

Answer 82

i believe this models a parabola of y=-16x^2
the change in y from 6 to 7 is how far it falls in 7th second
16(7^2) - 16(6^2) = 16(49-36) = 16(13) = 208

Answer 83

a rubber ball dropped 40 feet rebounds on each bounce 2/5 of the distance from which it fell. how far will it travel before comming to a rest?

Answer 84

geometric sequence
40+40(2/5)+ 40(2/5)^2 +...
looks like an infinite sequence before you get 0
lim n->inf (2/5)^n = 0
so in formula r^n = 0
a1=40
r=2/5
sum = 40 - 40(0) / 1-(2/5)
sum = 40 /3/5 = 200/3 = 66.666

Answer 85

what formula is that?

Answer 86

same as before
sum of geometric sequence

Answer 87

no but which one of mine because yours confuse me

Answer 88

\[s _{n}=\frac{a _{1}-a _{1}r^{n}}{1-r}\]

Answer 89

what would i put for n?

Answer 90

infinity

Answer 91

hu?

Answer 92

just substitute r^n=0

Answer 93

would my answer be iin feet?

Answer 94

yes

Answer 95

what does the graph for ..... look like?
-cubic with one real solution and two complex solutions look like?
-cubic with no real solutions?
-quartic with no real solutions?
-a quadratic with one real solution and one complex solution?
-a quartic with two real solutions and two complex solutions?
-a quadratic with no real solutions?
-a quartic with no real solutions?
-a cubic with 3 real solutions, but one is a double root?
-a quartic with for real roots, but both are double roots?

Answer 96

umm number of real solutions represents number of x_intercepts
cubic with no real solutions does not exist i believe