Question

A first number plus twice a second number is 11. Twice the first number plus the second totals 16. Find the numbers.

Answer 1

The first number, x, is equal to 7.

The second number, y, is equal to 2.

x + 2y = 11

2x + y = 16

We can subtract 2y from both sides of the first equation to get a value for x.

x = 11 - 2y

Because we have a value for x, we can plug it into the second equation.

2(11 - 2y) + y = 16

Distributive property.

22 - 4y + y = 16

Combine like terms.

22 - 3y = 16

Subtract 22 from both sides.

-3y = -6

Divide both sides by -3.

y = 2

Now that we have a value for y, we can plug it into either equation to solve for x.

x + 2(2) = 11

x + 4 = 11

Subtract 4 from both sides.

x = 7