Question

решите уравнения
1)(x+9)²-x(x+8)=1
2)(x-11)²=(x-7)(x-9)
3)(x-4)(x+4)-(x+6)²=-16
4)(1-3x)²-x(9x-2)=5

Answer 1

(x+9)²-x(x+8)=1
x²+18x+81-x²-8x=1
10x=-80/:10
x=-8

(x-11)²=(x-7)(x-9)
x²-22x+121=x²-8x-7x+63
x²-22x+121-x²+15x-63=0
-7x+58=0
-7x=-58
x=58/7
x=8 2/7

(x-4)(x+4)-(x+6)²=-16
x²-16-(x²+12x+36)=-16
x²-16-x²-12x-36+16=0
-12x-36=0
-12x=36/:(-12)
x=-3

(1-3x)²-x(9x-2)=5
1-6x+9x²-9x²+2x=5
-4x=4/:(-4)
x=-1