X+2y=5 x-3y=7 what is the value of the system determinant? a) -5 b) 1 c) 5

The answer is B) 1

Step-by-step explanation:

x-2y=5               x-3y=7

+2y=+2y

x-0=5+2y

x=5+2y

This problem says x is 5+2y, so substitute 5+2y for x in the other problem:

x-3y=7                   1. Put 5+2y in place of the x:

(5+2y)-3y=7           2. Now, remove the parenthesis:

5+2y-3y=7             3. Combine the y's:

5-y= 7  (2y-3y=-y) 4. Solve for y:

-5  =-5

0-y= 2

- (1)y=  2

     -1

y=-2                

5. Now that you know y is -2, you can put it in your problems to solve for x:

x-3y=7                   x-2y=5

x-3(-2)=7               x-2(-2)=5

x+6= 7                  x+4= 5

  -6=-6                    -4=-4

  x=1                       x=1