Question

Решите уравнение
(х-3)^2=16

Answer 1

По формуле
a^2 - b^2 = (a - b)(a + b) ==>

(x - 3)^2 - 4^2 = 0
(x - 3 - 4)(x - 3 + 4) = 0 
(x - 7)(x + 1) = 0 

x - 7 = 0 
x = 7 

x + 1 = 0
x = - 1