Question

1、多项式3X的平方-12与多项式X的平方-4X+4的公因式是（ ）2、已知（19X-31)(13X-17)-(13X-

Answer 1

3x^2-12 = 3(x^2-4) = 3(x+2)(x-2)

x^2-4x+4 = (x-2)^2

所以公因式是(x-2)

(19x-31)(13x-17) - (13x-17)(11x-23) = (13x-17)(19x-31-11x+23) = (13x-17)(8x-8) = 8(13x-17)(x-1)

所以A = 13,B = -17,C = -1

A+B+C= 自己算吧