solve the stsyem of equations by the substiution methed

Question

{4x+5y=-33}                                                                                                                                                                      {x=-4x}        

Answer 1

 

As written, the solution is x=0, y = -33/5;

You have the second equation as x=-4x which means x=0, 

which forces y= -33/5

 

If You meant y = -4x

 

4x + 5(-4x) = -33

4x + -20x = -33

-16x = -33

x=-33/16

 

Then y = (-4)(-33/16) = 33/4

The check step is 4x + 5y = 4(-33/16) + 5(33/4) = -33/4 + 165/4 = 132/4 = 33