Question

i need help please!!!!
solve using factoring,complete the square,square root property or quadratic formula.
A) x^2-4x+9=0
B) 1/5x-1/4x +1/3x =-17/60

Answer 1

the firrst one will have complex zeros (not real ones) is that ok?

Answer 2

can you explain to me please

Answer 3

is it \[x^2-4x+9=0\]?

Answer 4

yes

Answer 5

subtract 9 from both sides
get \[x^2-4x=-9\] not plus 9

Answer 6

omg, yes!! you are right! my mistake

Answer 7

then half of 4 is 2 and 2 squared is 4 so go right to
\[(x-2)^2=-9+4\] or \[(x-2)^2=-5\]

Answer 8

yes! thank you, is that the final answer for part A?

Answer 9

no

Answer 10

are you allowed complex numbers?

Answer 11

yes

Answer 12

\[(x-2)^2=-5\\
x-2=\pm\sqrt{5}i\\
x=2\pm\sqrt{5}i\]
last line is the "final answer "

Answer 13

does the i remain under the square root or does it come out?

Answer 14

the \(i\) is the outside the square root

Answer 15

\[\sqrt{-5}=\sqrt5\sqrt{-1}=\sqrt5i\]

Answer 16

oh okay

Answer 17

got it, thanks so much

Answer 18

could you also help me with B?

Answer 19

sure

Answer 20

is it \[\frac{1}{5}x-\frac{1}{4}x+\frac{1}{3}x=-\frac{17}{60}\]?

Answer 21

the x's are with the denominators, i dont know if that makes a difference

Answer 22

yes is certainly does!

Answer 23

\[\frac{1}{5x}-\frac{1}{4x}+\frac{1}{3x}=-\frac{17}{60}\]like that?

Answer 24

yes

Answer 25

multiply both sides by \(60x\)

Answer 26

** also, the negative on the right of the equal sign was in the numerator**sorry

Answer 27

that makes no difference

Answer 28

\[12x-15x+10x=-17x\]

Answer 29

each term is multiplied by 60x?

Answer 30

yes, but there is no solution

Answer 31

oh wait hold on

Answer 32

i made a mistake
multiply both sides by \(60x\) you get \[12-15+10=-17x\]you can solve that for \(x\)

Answer 33

you get \[-7=-17x\] and so \[x=\frac{7}{17}\]

Answer 34

i got that x should equal -1 :S

Answer 35

1/3x * 60x is 20

Answer 36

oops

Answer 37

i mean oops on my part

Answer 38

its okay :)
thank you!! you were such a huge help

Answer 39

\[12-15+20=17\] so you are right and i am wrong

Answer 40

yw