Question 4306
First, assign the variables:  

Let the two numbers be x and y

Then:  x - y = 2   Rewrite as: x = y + 2 and substitute into the 2nd equation.
  and  xy = 20

(y+2)y = 20
y^2 + 2y = 20
y^2 + 2y - 20 = 0  Solve by use of the quadratic formula:

{{{y=(-b+-sqrt(b^2-4*a*c))/(2*a)}}}

{{{y=(-2+-sqrt(-2^2-4*1*(-20)))/(2*1)}}}

{{{y=(-2+-sqrt(4+80))/(2)}}}

{{{y=(-2+-sqrt(4*21))/(2)}}}

{{{y=(-2+-2sqrt(21))/(2)}}}

{{{y=-1+-sqrt(21)}}}

x = y + 2

{{{x=2+(-1+-sqrt(21))}}}

{{{x=1+-sqrt(21)}}}