-4x-5y=-4 x=2y=4

Question

4-x-5y=-4

x+2y=4

Answer 1

-4x - 5y = -4

x + 2y = 4

 

Multiply the second equation by 4:

 

4*(x+2y = 4)

4x + 8y = 16

 

Now add the modified second equation to the first equation:

 

   -4x -  5y = -4

+ (4x + 8y = 16)

---------------------

     0  + 3y = 12

 

3y = 12

y = 4

 

To find x, plug y = 4 into either original equation and solve for x:

 

x + 2y = 4

x + 2(4) = 4

x + 8 = 4

x = -4

 

Check:

-4x - 5y = -4

-4(-4) - 5(4) = -4

16 - 20 = -4

-4 = -4     Check!

 

x + 2y = 4

-4 + 2(4) = 4

-4 + 8 = 4

4 = 4     Check!