Question

Sergio is 6 years older than Heather. In 6 years the sum of their ages will be 56. How old is Sergio now?

Answer 1

$\begin{gathered} \text{let} \\ \text{Heather age=x} \\ \text{Sergio age=6+x} \\ In\text{ 6 years} \\ x+6+(6+x+6)=56 \\ x+6+12+x=56 \\ 18+2x=56 \\ 2x=56-18 \\ 2x=38 \\ x=\frac{38}{2} \\ x=19 \\ \text{Sergio's age=6+19=25 years} \end{gathered}$