Question

.

Answer 1

add 64 to both sides
divide by 4
then take the square root of both sides

Answer 2

4r^2 - 64 + 64 = ?

Answer 3

start with 4r^2
take away 64
add 64 back

what's left?

Answer 4

no

Answer 5

we're solving for r

Answer 6

hint:

A - 64 + 64 = A
4r^2 - 64 + 64 = ?

Answer 7

follow the pattern

Answer 8

follow the pattern

if I start with A
take away 64
and add back 64,

I end up with A.

if I start with 4r^2
take away 64
add back 64

I end up with ____

fill in the blank

Answer 9

good!

so that means

4r^2 - 64 + 64 = 4r^2

so right now we have

4r^2 = 64

we divide both sides by 4 to get

r^2 = 16

so, what's the square root of 16?