w=winston's age
x=xavier's age
winston is 8 years older than xavier
w=8+x
in 2 years, winston will be twice as old as xavier
w+2=2(x+2)
we have
w=8+x and
w+2=2(x+2)
subsitute 8+x for w
w+2=2(w+2)
8+x+2=2(x+2)
x+10=2(x+2)
x+10=2x+4
minus x both sides
10=x+4
minus 4 both sides
6=x
sub back
w=8+x
w=8+6
w=14
winston is 14 years old now
xavier is 6 years old now