Question

Write an equation for the following problem. Then solve the equation and answer the problem. Find three consecutive integers with a sum of 21.

Short answer

The equation for the given problem is read $x+(x+1)+(x+2)=21$.

The three consecutive integers whose sum is 21 are 6,7,8.

Step-by-step solution

Step 1. Make the equation.

Assume that the smallest integer be x.

Therefore, the equation will be $x+(x+1)+(x+2)=21$.

Step 2. Find the value of x from the equation.

$\begin{array}{l}x+(x+1)+(x+2)=21\\ x+x+1+x+2=21\\ 3x+3=21\\ 3x=21-3\\ 3x=18\\ x=\frac{18}{3}\\ x=6\end{array}$

Write three consecutive integers whose sum is 21.

$\begin{array}{l}6+(6+1)+(6+2)=21\\ 6+7+8=21\end{array}$

The three consecutive integers whose sum is 21 are 6,7,8.