Question

The difference of two numbers is 18. Their sum is 66. What are the numbers? List the numbers from least to greatest.

Answer 1

attack_panic
·
5y
Another solution is to solve one equation for one variable, and plug that into the other equation.

x + y = 66
x = 66 - y

(66 - y) - y = 18
66 - 2y = 18
-2y = 18 - 66
-2y = -42
-2y/-2 = -42/-2
y = 24

Now that you have y, plug that into the first equation and solve for x.

x + 24 = 66
x = 66 - 24
x = 42

Then plug your two answers into both original equations to verify.

x + y = 66
42 + 24 = 66
66 = 66 check

x - y = 18
42 - 24 = 18
18 = 18 check