Question

the sum of five time a number and 15 is 40. Find the number

Answer 1

let the number be x
according to the question
15+5x=40
5x=25
x=5

hope it helps you

Answer 2

let the no. be x

then ,according to question 

5x+15=40
5x=40-15
5x=25
x=25/5
x=5
so the no. is 5