Question

Answer these questions step by step

Answer 1

Answer:

1) 21-3(a-7)=a+20

20a-147-30+21=a+20

20a-177+21=20

20a-156=20

20a=20+156

a=176/20

a=44/5

question 2)

5/x=7/x-4

5x-20=7x

2x=20

x=10

question 3)

5(8x+3)=9(4x+7)

40x+15=36x+63

40x-36x=63-15

4x=48

x=48/4

x=12

question 4)

3a-1/5=a/5+27/5

15a-1/5=a+25/5

15a-a=25+1

14a=26

a=26/14

a=2