one number is three less than four times another. if their sum is decreased by seven, the result is twenty. find the numbers

x = 21

y = 6

x = 4y - 3

x + y - 7 = 20

Because we have a value for x, we can put it in the second equation to find the value of y.

4y - 3 + y - 7 = 20

Combine like terms.

5y - 10 = 20

Add 10 to both sides.

5y = 30

Divide both sides by 5.

y = 6

Now we can place this value of y back into the equation to find the exact value of x.

x + 6 - 7 = 20

Combine like terms.

x - 1 = 20

Add 1 to both sides.

x = 21