The sum of two numbers is 21. The larger number is 6 less than two times a number. What are the two numbers?

I need two equations!

The value of the smaller number, y, is equal to 9. The value of the larger number, x, is equal to 12.

x + y = 21

x = 2y - 6

We have a value for x, so we can plug it into the original equation to solve for y.

2y - 6 + y = 21

Combine like terms.

3y - 6 = 21

Add 6 tot both sides.

3y = 27

Divide both sides by 3.

y = 9

Now that we have a value for x, we can plug it into the 2nd equation to solve for x.

x = 2 (9) - 6

x = 18 - 6

x = 12