小学数学题:用简便方法计算 (1+1.2)+(2+1.2*2)+(3+1.2*3)......(100+1.2*100)=


(1+1.2)喊伏+(2+1.2*2)桥或+(3+1.2*3)......(敏渗伍100+1.2*100)
=(1+2+3+...+100)+(1.2+1.2*2+...+1.2*100)
=(1+2+3+...+100)+1.2*(1+2+...+100)
=(1+2+3+...+100)*(1+1.2)
=(1+100)*100/2*2.2
=11110
(1+1.2)+(2+1.2*2)+(3+1.2*3)......(100+1.2*100)
= 1*(盯昌衫1+1.2)+2*(迅悔1+1.2)+3*(1+1.2)+4*(1+1.2)+......100*(凯腔1+1.2)
=(1+2+3+......+100)*(1+1.2)
=5050*2.2
=11110
=(1+2+3+...+100)+(1.2+12.*2+1.2*3+...+1.2*100)
=(1+2+3+...+100)+1.2*(1+2+3+...+100)
=(1+2+3+...+100)*(1+1.2)
=5050*2.2
=11110
原知贺源题=(搭态1+2+3···+100)拍姿+1.2*(1+2+3+···+100)
=5050+1.2*5050
=5110