The sum of 7 and a number divided by 3 is 10 find the number

x = number

( 7 + x ) / 3 = 10

Multiply both sides by 3.

7 + x = 30

Subtract 7 to both sides.

x = 23

Check result.

( 7 + x ) / 3 = ( 7 + 23 ) / 3 =

30 / 3 = 10