Question

wpn Learning. UIC 3. Solve by elimination. x + 2y = -7 x - 5y = 7 A. (-7,0) B. (-3, -2) C. (-2,-3) D. (0, -7)

Answer 1

x+2y=-7 ------> equation 1

x-5y=7 -------->equation 2

Change the signs in equation 2

x+2y=-7 ------> equation 1

-x+5y=-7 -------->equation 2

Add equation 1 and 2

x+2y=-7 ------> equation 1

-x+5y=-7 -------->equation 2

_________

7y=-14

y=-14/7

y=-2

Now substitute y=-2 in equation 1,

x+2(-2)=-7

x-4=-7

x=-7+4

x=-3

(x,y)=(-3,-2)

Option B is the correct answer.