Question

I really need help .. solve the equation.

Answer 1

story of my life

Answer 2

haha

Answer 3

I really cannot understand and get the correct answer.

1. x/4=x/9+5/4

2. 9x/4-x=x/32-7/8

solve the formula for the specific variable
3. F=9/5C+32 (solve for C)

4. A=P(1+nr) (solve for n)
please help !

I already know the answers for them I just want to understand how to do them.

Answer 4

this is how i would do question one...

Answer 5

??

Answer 6

\[\frac{x}{4}=\frac{x}{9} + \frac{5}{4}\]

get all the x's together

\[\frac{x}{4} - \frac{x}{9} = \frac{5}{4}\]

now get rid of the fractions, i hate fractions! so multiply everything through by 4 or 9, im going to do 4

\[x -\frac{4x}{9} =\frac{20}{4}\]

multiply everything through by 9 to get the other x term out of a fraction

\[9x - 4x =\frac{180}{4}\]

factor out the x's so i can just have one x

\[x(9-4) = \frac{180}{4}\]

tidy up abit.

\[x5 = 45\]

devide both by 5

\[x = \frac{45}{5}\]

\[x = 9\]

Answer 7

any stage you dont understand?

Answer 8

i understood all of it :) what about the next one? it seems more complex

Answer 9

is the first bit (9x/4) - x or 9x/(4-x) ?

Answer 10

its just the fraction 9x/4 then -x .. theres no parentheses or anything so its just 9x/4-x

Answer 11

cool

Answer 12

you have a go at this one. get all the x's on one side first.

Answer 13

ok if i do that then it will be 9x/4-x-x/32=-7/8 right?

Answer 14

exactly right. okay you can take the quick daring way, or the slow easy way. pick :)

Answer 15

(i did the slow easy way last time)

Answer 16

haha umm.. i dont know lets try quick daring way :)

Answer 17

good, alright so we have \[\frac{9x}{4} - x -\frac{x}{32} = -\frac{7}{8}\]

Answer 18

because we have all the x's together and none are on the bottom of any fractions we can just pull them all out in one go

Answer 19

because that equation is equivilant to this...
\[\frac{9}{4}\times x - 1 \times x -\frac{1}{32}\times x = -\frac{7}{8}\]

Answer 20

do you see how they are the same?

Answer 21

ok i gatcha so farr

Answer 22

sorry stupid website logged me out

Answer 23

okay so now we can just pull all the x's out like this
\[x(\frac{9}{4}\ - 1 -\frac{1}{32}) = -\frac{7}{8}\] sneaky right!

Answer 24

now we just have x times some other stuff. so we can divide both sides by the other stuff.

Answer 25

which is abit messy but is certainly quicker

Answer 26

\[x = -\frac{7}{8(\frac{9}{4}\ - 1 -\frac{1}{32})}\]

Answer 27

\[x = -\frac{7}{8(4.5 - \frac{33}{33} -\frac{1}{32})}\]

Answer 28

\[x = -\frac{7}{8(4.5 - \frac{32}{33})}\]

Answer 29

\[x = -\frac{7}{36 - \frac{256}{33}}\]

Answer 30

\[x = -\frac{7} {\frac{1188}{36} - \frac{256}{33}}\]

Answer 31

\[x = -\frac{7} {\frac{932}{33}}\]

Answer 32

sorry those others should have been 33 on the bottom not 36

Answer 33

i think ive messed it up lol
oops sorry. Do the first easy and slow way instead :P