계산(x+1)(3x-2)-(3x+1)(x-1)

계산(x+1)(3x-2)-(3x+1)(x-1)

(x+1)(3x-2)-(3x+1)(x-1)
=(3x+1)(x+1)-3(x+1)-(3x+1)(x-1)
=(3x+1)(x-1)+2(3x+1)-3(x+1)-(3x+1)(x-1)
=6x+2-3x-3
=3x-1