if x-y=3 and 2x+2y=2, then 3x-5y=

Question

 if x-y=3 and 2x+2y=2, then 3x-5y=what

Answer 1

x - y = 3

2x + 2y = 2

 

Multiply the first equation by -2 to get the system:  -2x + 2y = -6

                                                                                           2x + 2y = 2

 

Adding the equations, we obtain 4y = -4.  So, y = -1.

 

Substitute for y into either one of the given equations:  x - (-1) = 3

                                                                                              

So, x = 2

 

Solution:  3x - 5y = 3(2) - 5(-1) = 6 + 5 = 11