Randy and Sulley math question

Question

The sum of the ages of Randy and Sulley is 20. Randy’s age, decreased by twice Sulley’s age is 2. Find the age of Randy and Sulley.

Answer 1

Let Randy's age be R and Sulley's age be S.

We'll have:

R + S = 20

R - 2S = 2

Solve by methods of system of equation:

Subtract the second equation by first equation:

(R - R) + (S - (-2S)) = (20 - 2)

3S = 18

S = 6

Substitute the S = 6 into first equation:

R + 6 = 20

R = 14