Question

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

Answer 1

3 and 6

Explanation:

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

2x + 3y = 21 → (1)

x - y = 3 ( add y to both sides )

x = y + 3 → (2)

substitute x = y + 3 into (1)

2(y + 3) + 3y = 21

2y + 6 + 3y = 21

5y + 6 = 21 ( subtract 6 from both sides )

5y = 15 ( divide both sides by 5 )

y = 3

substitute y = 3 into (2)

x = 3 + 3 = 6

the numbers are 3 and 6