(2-х)^2-x(x+3)=18 решите уравнение

Question

(2-х)^2-x(x+3)=18 решите уравнение

Answer 1

4-4х+х^2-х^2-3х=18
-7х=18-4
-7х=14
х=-2

Answer 2

2^x + 2^(x-3) = 18
2^x (1+2^(-3)) = 18
2^x (1+1/8) = 18
2^x * 9/8 = 18
2^x = 18*8/9
2^x = 16
2^x = 2^4
x = 4