题目
计算或解比例。
(1)
(2018+ )×
(2)
+ + + +
(3)
=
答案: 2018+12016×12017 =2017+20162016+12016×12017 =(2017+20172016)×12017 =2017×12017+20172016×12017 =1+12026 =112016
112 + 120 + 130 + 142 + 156 =(13-14)+(14-15)+(15-16)+(16-17)+(17-18) =13-14+14-15+15-16+16-17+17-18 =13-18 =524
0.75x+1=14 解:x+1=0.75×4 x+1-1=3-1 x=2