Question

5. Mark's brother is five years older than Mark.

Answer 1

Answer:

9

Step-by-step explanation:

Let's say Mark is M and his brother is B.

M+5=B

M+B=23

Now we can solve using subsitution.

M+M+5=23

(Subtract 5 from both sides)

2M=18

M=9

Hope this helped!