Question

HELP PLEASE. What is the value of the x variable in the solution to the following system of equations?
7x - 2y = 21
4x + y = 57

Answer 1

Can you solve an equation like this?
2x+1=7

Answer 2

yes. x = 3

Answer 3

Yes. So this is the same thing. Except now you need to isolate ONE variable.(Bring it on one side) because you can only solve equations with ONE variable.

Answer 4

So: 7x = 21 + 2y
x = (21+2y)/7

Answer 5

i thought you subtract 7x - 4x

Answer 6

now you have X by itself. So then, put the NEW x equation (the one we just made) into the OTHER equation.
So:

4x + y = 57
4((21+2y)/7) + y = 57

Answer 7

now solve for y

Answer 8

why subtract ?

Answer 9

i have to do one equation at a time, i didnt know that
now i understand
i do the first equation then put it in to the second

Answer 10

i got 15 as the answer

Answer 11

Let me checl

Answer 12

The answer should be different. Try it again

Answer 13

When you find the right values for x and y, you will find that the equations are both true.