Question

Jamar is four times as old as Josh. In 20 years he will be twice as old as Josh. How old is Jamar?

Answer 1

simultaneous equations
Jamar=J
Josh=j
4J=j
20+J=2j
Then
4J=j
-4 (J)=-4(2j-20)
So
0=-7j+80
7j=80
j=80÷7