Question

а^2+b^2=240 i a-b=12,то a+b=

Answer 1

a - b = 12

a² + b² = 240

возводим в квадрат

a² - 2ab + b² = 144

240 - 144 = 2ab

2ab = 96

ab = 48

a + b = x

(a + b)² = a² + 2ab + b² = 240 + 96 = 336

a + b = ±√336