Question

how do i get that answer? 0_o

Answer 1

Well, (-1/2)/2 is the same as (-1/2) * (1/2)

Answer 2

Now square that.

Answer 3

division by 2 means multiplication by 1/2
so (-1/2)*(1/2)=-1/4
now square it.

Answer 4

1/16... so -31/2 it would be (-31/2)*(31/2)=-961/4?

Answer 5

I'm not sure what the second part is there at all, but (-31/2)^2 = 240.25 in decimal form.

Answer 6

Is that some separate equation? part of another problem? what is that?

Answer 7

yes let me take a pic

Answer 8

oh wait

Answer 9

keep it as 961/4 only.

Answer 10

(1/7) should be multiplied to all 3 terms and not only to 7x^2

Answer 11

ooh and do the same thing with -217? right?

Answer 12

where did u get -217 from ?

Answer 13

wait do i multiply by 7 or just -37/7?

Answer 14

why is there need to multiply 1/7 on both sides ?

Answer 15

so i can get rid of the 7 and be left with x^2

Answer 16

@cos00155079 you want to create a perfect square term
\[7x^2-31x-20=0\]
multiply both sides by 1/7 or divide by 7
\[\frac{1}{7}(7x^2-31x-20)=0\times \frac 17\]
we get
\[x^2-\frac {31}7 \ \ \ x-\frac {20}{7}\ =0\]
do you get this?

Answer 17

yup

Answer 18

now half the x term and add and subtract the square of it
\[\frac{-31}{7}\\ \div 2=\frac{-31}{14}\]
square it
\[{(\frac{-31}{14})}^2\]
now add and subtract this on the left side, do you get this?

Answer 19

yes!! let me solve it from here..try to..

Answer 20

good, take your time:)
let me know if you need help :)

Answer 21

ok but if i square that -31/14 that gives me 961/196???

Answer 22

yeah, you're right