developer : A = x (3x-1)-(x+5)(6x-2)
A=x(3x-1)-(x+5)(6x-2)
A=3x²-x-(6x²+30x-2x-10)
A=3x²-x-(6x²+28x-10)
A=-3x²-29x+10
x(3x-1)-(x+5)(6x-2)
= 3x²-x-(6x²+2x+30x-10)
=3x²-x-(6x²+28x-10)
=-3x²-29x+10
