Solve by elimination
x+5y=-13
2x-5y=-20

x+5y=-13= (x=−5y−13)

   2x-5y=-20= (x=5/2y-10)        

Step-by-step explanation: The answers are labeled in parenthesis. According to my calculations, this is what I got. Sorry for any inconvenience.

x+5y=-13 (1)

2x-5y=-20(2)

adding equation 1 and 2

x+5y+2x-5y=-13-20

3x=-33

x=-33/3=-11answer

multiplying equation 1 by 2 and adding equation 1&2

2x+10y-2x-(-5y)=-26-(-20)

10y+5y=-26+20

15y=-6

y=-6/15=-2/5answer

answer: evaluate the objective function at each vertex to determine which - and -values, if any, maximize or minimize the function. example: find the minimum value and maximum value of the objective function f ( x , y ) = 4 x + 5 y , subject to the following constraints