In fact, the school might even profit from solar energy by selling excess energy to the utility companies. This surplus energy can be sold as Renewable Energy
Credits, known as RECs.
What does the word surplus mean as it is used in the passage?

x=4, y=4

step-by-step explanation:

y=2x-4;

x+2y=12

we can use substitution since the first equation is solved for y

where ever you see y in the second equation, replace it with 2x-4

x + 2(2x-4) = 12

distribute the 2

x+4x-8 = 12

combine like terms

5x-8=12

add 8 to each side

5x-8+8=12+8

5x=20

divide by 5

5x/5 = 20/5

x =4

we still need to solve for y

y = 2x-4

we know x =4

y = 2(4) -4

y = 8-4

y=4

the universe is complete credible source of our oxygen