^2 - в квадрате
(х+3)2-16
x^2 + 2*x*3 + 3^2 - 16= x^2 + 6x - 7=0
(1-2х)2
1^2 - 2*1*2x + 2x^2= 1 - 4x +2x^2= 2x^2 - 4x + 1
x^2 + 6x - 7 = 2x^2 - 4x + 1
x^2 - 2x^2 + 6x - 4x -7 +1=0
-x^2 + 2x - 6=0|:(-1)
x^2 - 2x + 6=0
x^2 = 2x - 6|:2
x^2 = x - 3
x^2 - x= -3
x=-3
^2 - в квадрате
(х+3)2-16
x^2 + 2*x*3 + 3^2 - 16= x^2 + 6x - 7=0
(1-2х)2
1^2 - 2*1*2x + 2x^2= 1 - 4x +2x^2= 2x^2 - 4x + 1
x^2 + 6x - 7 = 2x^2 - 4x + 1
x^2 - 2x^2 + 6x - 4x -7 +1=0
-x^2 + 2x - 6=0|:(-1)
x^2 - 2x + 6=0
x^2 = 2x - 6|:2
x^2 = x - 3
x^2 - x= -3
x=-3