问题 解答题
①18+15x=21 ②(x+1.2)×5=36③24x-8x=28.8
④8x÷0.6=2.4⑤4x-3×1.2=6.8 ⑥15x+3.8×12=87.6.
答案

①18+15x=21,

18+15x-18=21-18,

15x=3,

x=0.2;

②(x+1.2)×5=36,

(x+1.2)×5÷5=36÷5,

x+1.2=7.2,

x+1.2-1.2=7.2-1.2,

x=6;

③24x-8x=28.8,

16x=28.8,

16x÷16=28.8÷16,

x=1.8;

④8x÷0.6=2.4,

8x÷0.6×0.6=2.4×0.6,

8x=1.44,

8x÷8=1.44÷8,

x=0.18;

⑤4x-3×1.2=6.8,

4x-3.6=6.8,

4x-3.6+3.6=6.8+3.6,

4x=10.4,

4x÷4=10.4÷4,

x=2.6;

⑥15x+3.8×12=87.6,

15x+45.6=87.6,

15x+45.6-45.6=87.6-45.6,

15x=42,

15x÷15=42÷15,

x=2.8.

单项选择题
单项选择题