Question

Решите уравнение -4/7x в квадрате + 28 =0

Answer 1

-4/7x^2 + 28 = 0,
-4/7x^2 = - 28,
x^2 = - 28 : (-4/7),
x^2 = 28 * 7/4,
x^2 = 49,
x1 = \/49 = 7,
x2 = - \/49 = - 7