Question

The sum of two numbers is 28. The first number, x, is three
times the second number, y.

Answer 1

x=21

y= 7

Explanation:

x+y = 28

x = 3y

Substitute the second equation into the first

3y+y = 28

4y = 28

Divide by 4

4y/4 = 28/4

y = 7

Now we need to find x

x = 3*y

x = 3*7

x = 21