Решите уравнение:(х+4)2=4х2+5

Question

Решите уравнение:(х+4)2=4х2+5

Answer 1

(x+4)^2 = 4x^2 + 5
x^2 + 8x + 16 = 4x^2 + 5
3x^2 - 8x - 11 = 0
D = 8^2 - 4*3(-11) = 64 + 12*11 = 64 + 132 = 196 = 14^2
x1 = (8 - 14)/6 = -6/6 = -1
x2 = (8 + 14)/6 = 22/6 = 11/3