Question

The difference of four times a number and five is 15. What is the number?

Answer 1

Assume that the number is x

Four times the number means multiply x by 4

`4* x=4x`

The difference between 4 times the number and 5 means subtract 5 from 4x, then equate the difference by 15

`4x-5=15`

Now, we will solve the equation to find x

Add 5 to both sides

`\begin{gathered} 4x-5+5=15+5 \\ 4x=20 \end{gathered}`

Divide both sides by 4

`\begin{gathered} (4x)/(4)=(20)/(4) \\ x=5 \end{gathered}`

The number is 5