Thu gọn
A(x) = 5 +3x2 – x - 2x2
A(x) = 5+x2-x
A(x) = x2-x+5
B(x) = 3x + 3 – x – x2
B(x) = ( 3x-x) + 3 - x2
B(x) = 2x+3-x2
B(x)= -x2 + 2x+3
\(A(x) = 5 +3x^2 – x - 2x^2 = 5 + ( 3^2 - 2x^2 ) - x = x^2 -x+5\)
\( B(x) = 3x + 3 – x – x^2 = ( 3x-x ) + 3 - x^2 = 2x + 3 - x^2 = -x^2 + 2x +3\)