Question

@shelby1290

Answer 1

Solve each system of linear equations by elimination.
3a - 2b + 4 = 0
2a - 5b - 1 = 0

Answer 2

Ok, so first multiply the second equation by -3.

Answer 3

-6a- (-15) - -3 =0

Answer 4

Pretty close, you know that subtracting a negative number is the same as adding right?

Answer 5

So is it -6a+15-(-3)=0

Answer 6

or -6a+15+3=0

Answer 7

-6a + 15b + 3 = 0

Answer 8

Ok, now multiply the first equation by 2, that way the a's will cancel

Answer 9

6a-4b+8=0

Answer 10

Yep, now we vertically add them
6a - 4b + 8
-6a + 15b + 3
that equals to
11b + 11 = 0

Answer 11

Now how do we get 11 to the other side?

Answer 12

change it to a negative?

Answer 13

Yep, subtract 11 from both sides :)

Answer 14

11b=0-11

Answer 15

Yes! So, now divide by 11, and we get b

Answer 16

b=-1

Answer 17

0-11 =-11
-11/11 = -1

Answer 18

Yes. Some substitution is required in the elimination method, but only after we have found the value of one of the variables. So substitute in -1 for b into one of the original equations

Answer 19

ok I'll use the first one
3a -2b+4=0
3a - 2(-1) + 4=0

Answer 20

Ok, now solve and you get,
3a + 2 + 4 = 0
3a + 6 = 0
-6
3a = -6
a = ?

Answer 21

-2

Answer 22

Yep :)
so the final solution is a = -2, b = -1, or if they want coordinates, -2, -1. I appreciate your patience through all of this, since he was just going straight out substitution, I wanted to show you the correct way to do it.

Answer 23

Thank you sooo much! :)

Answer 24

No problem! If you need anything else, just let me know through PM or tag me.

Answer 25

good luck @shelby1290 would you mind fanning me please?

Answer 26

@shelby1290

Answer 27

did you get the notification?

Answer 28

yea i see that you've blocked me

Answer 29

ah, it made you unfan me

Answer 30

just fanned you back