求四道初二的整式计算题,十万火急,写出计算过程,1(x+3)乘(x-5)2(x+2)乘(x+5)3(2m+3)乘(m-4)4(x+1)乘(x+2)

问题描述:

求四道初二的整式计算题,十万火急,写出计算过程,
1(x+3)乘(x-5)
2(x+2)乘(x+5)
3(2m+3)乘(m-4)
4(x+1)乘(x+2)

(x+3)(x-5)=x×x-x×5+3×x-3×5=x²-5x+3x-15=x²-2x-15(x+2)(x+5)=x×x+x×5+2×x+2×5=x²+5x+2x+10=x²+7x+10(2m+3)(m-4)=2m×m-2m×4+3×m-3×4=2m²-8m+3m-12=2m²-5m-12(x+1)(x+2)=x...