Question

twice one number added to three times another gives 21 find the numbers if the difference between them is 3

Answer 1

6 and 3

Explanation:

let x and y be the 2 numbers with x > y , then

2x + 3y = 21 → (1)

x - y = 3 → (2)

Multiplying (2) by 3 and adding the result to (1) will eliminate y

3x - 3y = 9 → (3)

Add (1) and (3) term by term to eliminate y

5x = 30 ( divide both sides by 5 )

x = 6

Substitute x = 6 into either of the 2 equations and solve for y

Substituting into (1)

2(6) + 3y = 21

12 + 3y = 21 ( subtract 12 from both sides )

3y = 9 ( divide both sides by 3 )

y = 3

The 2 numbers are 6 and 3