Question

若多项式为4x的2次方-6xy+2x-3y与ax的2次方+bxy+3ax-2by的和不含二次项,则这两个多项式的和为?

Answer 1

和=(4x²-6xy+2x-3y)+(ax²+bxy+3ax-2by)=(4+a)x²+(b-6)xy+(2+3a)x-(3+2b)y前两项是二次项所以他们的系数是0所以4+a=0,b-6=0a=-4,b=6所以和=0×x²+0×xy+(2-3×4)x-(3+2×6)y=-10x-15y...