What two numbers add to make twenty and have a difference of four?
smaller number = a0 and larger number = a1

Step-by-step explanation:

According to question, let smaller number be and larger number be .

Given that sum of two numbers is 20 and difference is 4, we get equations as

follows:

From first equation , we get

On putting this in the second equation, we get

On putting in equation , we get

So, two numbers whose sum is 20 and difference is 4 are 12 and 8

solve systems of equations by graphing. a system of linear equations contains two or more equations e.g. y=0.5x+2 and y=x-2. the solution of such a system is the ordered pair that is a solution to both equations. to solve a system of linear equations graphically we graph both equations in the same coordinate system