Question

three less than triple a number is the same as the number plus 57. What is the number?

Answer 1

make this into an equation keeping the number as x
3x-3 = 57+x
3x-x = 57+3
2x=60
x= 30

prove this by substituting the x 
30*3 -3 =57+30
87=87
there you have it :)