Question

Решите уравнение x^2+21x+4=−4x^2

Answer 1

x^2 + 4x^2 + 21x + 4 = 0
5x^2 + 21x + 4 = 0
D = 441 - 4*5*4 = 441 - 80 = 361
x1 = - 21 + 19 / 10 = - 2/10 = -1/5
x2 = -21 -19 / 10 = -40/10 = -4