Question

1) (x + 1)2 = (2x - 1);
3) 15(x + 1)2 = 15x2 + 17;

Answer 1

$\bf~1)~~(x+1)^2=(2x-1);\\x^2+2x+1=2x-1;\\x^2+1=-1;\\x^2=-1-1;\\x^2=-2\to~x\in\varnothing.\\\\\bf~2)15\cdot(x+1)^2=15x^2+17;\\15\cdot(x^2+2x+1)=15x^2+17;\\15x^2+30x+15=15x^2+17;\\30x+15=17;\\30x=17-15;\\30x=2;\\x=\dfrac{2}{30} =\dfrac{1}{15} .$