two numbers, x and y:
their quotient (x/y) is 20
x/y = 20... x = 20y
their sum (x+y) is 84
x+y = 84
Now substitute one equation into the other:
x+y = 84, x = 20y
(20y)+y = 84
21y = 84
21y/21 = 84/21
y = 4
x = 20y = 20(4) = 80
So check by plugging into:
x+y = 84
80+4 = 84... CORRECT!
So the two numbers are 80 and 4