Question

(2-x) la puterea a doua + 4(x-1)-x la puterea a doua

Answer 1

$(2-x)^2+4(x-1)-x^2=2^2-2 \cdot 2 \cdot x+x^2+4x-4-x^2= \\ 4-4x+x^2+4x-4-x^2=0$