Question

X+y=10 and 2x+4y=30
What are the steps to solve this equation?

Answer 1

x=5 and y=5

Explanation:

You "plug" one equation into the other, to get a new equation that only has one variable (x or y), then you can simplify that and have your answer.

So let's plug the first into the second:

First, we convert the first equation into an x=... form. For this one, this means moving the +y to the other side:

x = 10 - y

Now we substitute 10-y for x in the second equation:

So 2x+4y=30 becomes:

2(10-y) + 4y = 30

And simplify that:

20 - 2y + 4y = 30

20 + 2y = 30

2y = 30-20

2y = 10

y = 5

This is the first answer! If we put this into the first equation, we get:

x = 10 - 5 = 5

Now we have both answers, x=5 and y=5