Question

10) Choose the solution for each linear system.

(3,0)
(-3,-1)
(2,-1)
(-2,1)
(x-2y=4
4x + 2y = 6
11) Choose the solution for each linear system.
(2,4)
O(-2,-4)
O (4,2)
O(-4,-2)
[6x-2y = -4
-4x+3y=-4

Answer 1

10. C. (2, -1)

11. B. (-2, -4)

Explanation:

10.

`\left \{ {{x-2y=4} \atop {4x+2y+6}} \right.`

The y values cancel out if you add the equations

5x = 10

x = 2

plug in x

2 - 2y = 4

-2y = 2

y=-1

Answer: C. (2, -1)

11.

`\left \{ {{6x-2y=-4} \atop {-4x+3y=-4}} \right.`

In order to get terms to cancel out, multiply the top by 3 and bottom by 2

`\left \{ {{18x-6y=-12} \atop {-8x+6y=-8}} \right.`

The y values cancel out if you add the equations

10x = -20

x = -2

plug in x

6(-2) - 2y = -4

-12 - 2y = -4

-2y = 8

y = -4

Answer: B. (-2, -4)