(2.15﹢5.17+3.62)×(5.17+2.15+8.5)-(3.62+2.15+8.5+5.17)×(2.15+5.17)用简便方法计算

问题描述:

(2.15﹢5.17+3.62)×(5.17+2.15+8.5)-(3.62+2.15+8.5+5.17)×(2.15+5.17)用简便方法计算

原式=[(2.15+5.17)+3.62]×[(2.15+5.17)+8.5]-[3.62+8.5+(2.15+5.17)]×(2.15+5.17)=(2.15+5.17)²+3.62×(2.15+5.17)+8.5×(2.15+5.17)+3.62×8.5-[3.62×(2.15+5.17)+8.5×(2.15+5.17)+(2.15+5.17)²...