Question

Help with number 70
Step by step please

Answer 1

H. r² + s² = 34

Explanation:

We know:

`(r+s)^2=r^2+2rs+s^2`

We have:

`rs=15\\\\(r+s)^2=64`

Substitute:

`64=r^2+2(15)+s^2`

`64=r^2+30+s^2` subtract 30 from both sides

`34=r^2+s^2`

Answer 2

r^2 +s^2 = 34

Explanation:

(r+s) ^2

We can FOIL

first = r*r = r^2

outer r*s =rs

inner = s*r =rs

last = s*s =s^2

Add them together

r^2 +2rs + s^2

(r+s) ^2 = r^2 +2rs+s^2 = 64

We are given that rs = 15

so 2*rs = 2 (15) = 30

r^2 +30 + s^2 = 64

Subtract 30 from each side

r^2 +30-30 + s^2 = 64-30

r^2 +s^2 = 34