Question

Solve the system using elimination.
{-8-6x=-7y
1/2=-x+3/4y
Please help!

Answer 1

First, rewrite both equations in the form ax + by = c. Can you do that?

Answer 2

yeah i can do that,
-8=6x-7y
1/2=-x+ 3/4 y

Answer 3

so then i multiplied the second equation by 6 to elminate the "x" but I keep getting lost, am i even in the right ball park

Answer 4

Great. Let's just switch sides on both equations.

\( 6x - 7y = -8\)

\(-x + \dfrac{3}{4}y = \dfrac{1}{2} \)

Answer 5

Correct.

Answer 6

So then its
-6x+4.5y=3
then I subtract from orginal equation to get
-2.5y=-5, y=2 ???

Answer 7

\( 6x - 7y =8\)

\(-6x + 4.5x = 3\)

Answer 8

Now add the equations together.

2.5x = 5
x = 2

Answer 9

okay then u plug x into first equation?

Answer 10

Yes.

Answer 11

6x-7y=8
6(2)-7y=8
12-7y=8
-7y=-4
y=4/7 or .571 ??? So x=2 and y = 4/7 ???

Answer 12

Wait. There's a mistake from before.

Answer 13

yeah thought so, can't answer this question for the life of me!!!

Answer 14

-8-6x=-7y ------> 6x - 7y = -8 (remember the -8, not 8)
1/2=-x+3/4y ------> -x + 0.75y = 0.5

Now we muiltiply tghe second equation by 6, and keep the first one the same:

6x - 7y = -8
-6x + 4.5y = 3
----------------------(add)
-2.5y = -5

y = 2

Answer 15

Now we substitute x = 2 into the first equation:
6x - 7(2) = -8
6x - 14 = -8
6x = 6
x = 1

Answer 16

so y=1 and x=2 ?

Answer 17

or wait its y=2 and x=1 !

Answer 18

Right mathstudent55? that y=2 and x=1

Answer 19

Correct.
x = 1 and y = 2

Answer 20

Thank you so much, kept messing up this problem!

Answer 21

You're welcome.