Algebra-1

To determine Alex's current age, we can set up an equation.

 

Let x be Alex's current age. Since Alex is 8 years older than his sister, his sister's age can be expressed as x − 8.

 

In 5 years, Alex's age will be x + 5 and his sister's age will be (x − 8) + 5, which simplifies to x − 3.

 

Set up the equation for their combined age in 5 years:

(x + 5) + (x – 3) = 78

&n...