A+b=15----(1)
a*b=54----(2)
(1) a=15-b ----(3)
put(3) in(2)
(15-b)*b=54
15b-b^2=54
b^2-15b+54=0
(b-9)(b-6)=0
so b=9 or b=6
if b=9 then a=15-9=6
if b=6 then a=15-6=9
answer two numbers are 6 and 9
B. it’s the change in y over the change in x
5x+ (5)15
or
5(x+15)
I hope this helps