Question

Consider the following word problem: Eleven more than four times a number is equal to the difference between - 21 and four times the number. Find the number.

Answer 1

Let the unknown number be x

Eleven more than four times the number is expressed as:

`4x+11`

The difference between -21 and four times the number is expressed as:

`-21-4x`

Combing the above expressions together, to solve for x will give us:

`\begin{gathered} 4x+11=-21-4x \\ \text{Collect like terms:} \\ 4x+4x=-21-11 \end{gathered}`

Simplifying further, we will have:

`\begin{gathered} 8x=-32 \\ (8x)/(8)=(-32)/(8) \\ x=-4 \end{gathered}`

The number, therefore, is -4