Question

解方程,2.55÷x=0.4 ,13x-2x-7x=26 ,0.21x6+16x=50.86,6x-1.5（x+10）=

Answer 1

2.55÷x=0.4

x=2.55÷0.4

x=6.375

13x-2x-7x=26

4x=26

x=26÷4

x=6.5

0.21x6+16x=50.86

1.26+16x=50.86

16x=50.86-1.26

x=49.6÷16

x=3.1

6x-1.5（x+10）=5.7

6x-1.5x-15=5.7

4.5x=5.7+15

x=20.7÷4.5

x=4.6