Question

Solve the system using Elimination

2x +6y=-12
5x-5y=10

A) 2,1
B) 0,-2
C) -2,0
D) 1,2

Answer 1

B) 0,-2 (x = 0 , y = -2)

Step-by-step explanation by elimination:

Solve the following system:

{2 x + 6 y = -12 | (equation 1)

{5 x - 5 y = 10 | (equation 2)

Swap equation 1 with equation 2:

{5 x - 5 y = 10 | (equation 1)

{2 x + 6 y = -12 | (equation 2)

Subtract 2/5 × (equation 1) from equation 2:

{5 x - 5 y = 10 | (equation 1)

{0 x+8 y = -16 | (equation 2)

Divide equation 1 by 5:

{x - y = 2 | (equation 1)

{0 x+8 y = -16 | (equation 2)

Divide equation 2 by 8:

{x - y = 2 | (equation 1)

{0 x+y = -2 | (equation 2)

Add equation 2 to equation 1:

{x+0 y = 0 | (equation 1)

{0 x+y = -2 | (equation 2)

Collect results:

Answer: {x = 0 , y = -2