Question

x²-y².se x-y=7 e x +y=8​

Answer 1

x²- y² =

(15/2)² - ( 1/2)² =

(15×15/2×2) - ( 1×1/2×2) =

225/4 - 1/4 =

225 - 1 /4 =

224/4 = 56

x- y =7

( 8 - y ) - y = 7

8 - y - y = 7

8 - 7 = + y + y

1 = 2y

2y = 1

y = 1/2

x +y=8

x = 8 - y

x = 8 - (1/2)

x = 8 - 1/2

x = 16 - 1 /2

x = 15/2