Question

solve the system of equations and choose the correct ordered pair.
3x-4y=26
2x+8y=-36
A.(2,-5)
B.(2,5)
C.(6,2)
D.(6,-2)

Answer 1

So for this, I will be doing the elimination method. Firstly, multiply both sides of the first equation by 2:

$6x-8y=52\\2x+8y=-36$

Next, add the two equations together to get $8x=16$ . From here you can solve for x.

For this equation, just divide both sides by 8 and your first answer will be $x=2$

Now that we have the value of x, substitute it into either equation to solve for y:

$3*2-4y=26\\6-4y=26\\-4y=20\\y=-5\\\\2*2+8y=-36\\4+8y=-36\\8y=-40\\y=-5$

In short, the solution is (2,-5), or A.

Answer 2

3x-4y=26

2x+8y=-36

We will solve this system with gaus algorithm

We multiply first equation with number 2 and we get

6x-8y=52 => we add second equation to this and we get

8x=16 => x=2 => we replace x=2 in first equation and we get

3*2-4y=26 => 6-4y=26 => -4y=20 => y=-5

The correct answer is A.

Good luck!!!