Question

Find the three consecutive interger such that the sum of the first and third is 80

Answer 1

We will call the first number "x".

Thus, since the numbers have to be consecutive, the second integer will be "x+1", and the third integer "x+2".

We need for the sum of the first "x" and the third "x+2" to be equal to 80, so we will have the equation:

`x+x+2=80`

And now we solve this equation to find x.

First, add the like terms on the left side:

`2x+2=80`

Subtract 2 to both sides:

`\begin{gathered} 2x+2-2=80-2 \\ 2x=80-2 \\ 2x=78 \end{gathered}`

Divide both sides by 2:

`\begin{gathered} (2x)/(2)=(78)/(2) \\ x=(78)/(2) \\ x=39 \end{gathered}`

We have the first integer: 39

Thus, the second number is: 39+1=40

And the third number: 39+2=41

Answer: 39, 40 and 41