Identify the solution(s) of the system of equations, if any.

Question

9x+2y=6

8x-2y=6

 

Possible answers:

 

17/12, -27/8

0,3

12/17, -3/17

12,-51

Answer 1

Ways to solve a system of simultaneous equations in two variables include 1. elimination, 2. graphical, 3. substitution and 4. using matrices to name a few. For this one substitution is the best one.

9x + 2y =6

8x - 2y =6  to eliminate the two Y coefficients we add them,

17x = 12

X=12⁄17. to find Y substitute 12⁄17 in 9x + 2y = 6, 9(12/17) +2Y =6, therefore, Y = -3/17

 

Answer 2

9x+2y=6

8x-2y=6

add the equations

17x=12

x=12/17

(9)(12/17)+2y=6

108/17+2y=6

2y=6-108/17

2y=6-(6 6/17)

2y=-6/17

y=-6/34

y=-3/17

12/17 and -3/17