Question

Help me please. i'm confused on how to do elimination. This is algebra 2

Solve the systems using elimination

1) 8x - 6y= -20
-16x + 17y = 30

2) -4y - 11x = 6
20= -10x - 10y

Answer 1

For the first problem, multiply the top equation by 2, so the resulting equation is 16x-12y = -40. You notice that if you add the bottom equation to the top equation, the X’s cancel out, resulting in the equation: 5y = -10, so y = -2. Plug -2 into y, and x = -4. For the second problem, you can multiply the top equation by 5 resulting in: -20y-55x = 30. The bottom equation can be multiplied by -2 resulting in: 20y+20x = -40. Notice that the y’s can cancel if the top and bottom equation are added together.

Answer 2

1. y = 8/11x + 10/11

2. y = -3/2x - 13/7

Explanation:

1. -8x + 11y = 10

Add 8x to both sides

11y = 8x + 10

Divide both sides by 11

y = 8/11x + 10/11

2. 6 = -4y - 11x

20 = -10x - 10y

26 = -14y - 21x

Add 21x to both sides

-14y = 21x + 26

Divide both sides by -14 and simplify!

y = -3/2x - 13/7