A system of equations is given below.
2x + 7y = 1
-3x – 4y = 5

Question

A system of equations is given below.
 2x + 7y = 1
-3x – 4y = 5

anonymous · Answer

A). multiply the first equation by 3. + 6x +21y = 3 
Add to the second equation. in order to do this, one of your variables needs to have the same number so they can cancel. multiply the second equation by 2. 
-6x -8y= 10 

A./B. Now you can add them and solve. 6x + 21y = 3
                                                      + -6x - 8y   =10
                             
                                                                   13y = 13 
                                                                        y=1 
Now that you know the value of 1 variable, you can solve for the other variable. Just substitute the y=1 in for 1 in the first equation. 

6x +21(1) = 3 
            6x = -18
             x = -3

C. Prove that it equals the first equation. Just plug in the values into the original equation. 

2x + 7y =1    x = -3 and y = 1 

2(-3) +7(1) = 1 
                1 = 1

anonymous · Answer

Thank you SO much!! This makes sense!!

anonymous · Answer

You're welcome! :) I'm glad!