Question

Find x in ecuation 4x+30=40

Answer 1

2.5

4x+30=40

   -30  -30

4x=10

/4   /4

x=2.5

Answer 2

4x+30=40

What you would do is subtract 30 from 30 and 40 which would give you 10 and then what you would do is divide the 10 by 4 to get 2.5.  Therefore X=2.5.  And to check your work you would plug in 2.5 in place of X and the answer to that equation should be 10.