Question

(5-y)ao quadrado -2y2=14

Answer 1

(5-y)² - 2y² = 14

25 - 10y + y² - 2y² - 14 = 0 ==> - y² - 10y + 11 = 0

Δ = (-10)² - 4.(-1).11 = 100+44 = 144

y = 10+/-12
         - 2

y1 = - 11   ;  y2 = 1