Question

Solve the system of linear equations using elimination.

10x + 7y = 12
8x + 7y = 18
A) (3, 6)
B) (3, −6)
C) (−3, 6)
D) (−3, −6)​

Answer 1

Answer:

C. (-3,6)

Step-by-step explanation:

Take 10x + 7y = 12 as first equation and 8x + 7y = 18 as second equation.

Subtracting both equations, you will get

10x + 7y - 8x - 7y = 12 - 18

2x = -6

x = -3

Substitute value of 'x' in any of the given equation :-

10x + 7y = 12

10 * -3 + 7y = 12

7y = 12 + 30

y = 42/7

y = 6

Answer 2

Answer:

C) (−3, 6)

Step-by-step explanation:

10x + 7y = 12 ___ (−3, 6)

10×(-3) + 7×6 = -30 + 42 = 42 - 30 = 12

8x + 7y = 18 ___ (−3, 6)

8×(-3) + 7×6 = -24 + 42 = 42 - 24 = 18