Question

solve each system by substitution be sure to give your solution as an ordered pair

3x+y=10
x-y=-6

Answer 1

u multiply 3 * x?

Answer 2

2 because 3 * 2 = 6 and 6 + 4 = 10

Answer 3

so x = 2

Answer 4

ok what about y

Answer 5

where did u get the 2 from

Answer 6

isnt x 1

Answer 7

3x+y=10
x-y=-6
--------
4x = 4
x = 1

x = 1 in x - y = -6
1 - y = -6
-y = -7
y = 7

Answer 8

S={1,7}

Answer 9

Did you get it?

Answer 10

yes.

Answer 11

Good

Answer 12

can you help me work through one more though

Answer 13

yes sure

Answer 14

x-y=1
x-3y=9

Answer 15

make it 2x?

Answer 16

yep, you can multiply one of them by -2

Answer 17

so what would it look like

Answer 18

-3 * -2?

Answer 19

First, you can choose which equation do you want to multiply in order for you to exclude x. Let's try the first one.
x-y=1
Now multiply by -2: -2(x) -2(y) = -2(1)
Can you multiply it?

Answer 20

-2

Answer 21

you get -2x -2y = -2
did you understand why?

Answer 22

u just multiply

Answer 23

yup, you should have done that. now can you sum the multiplied equation with the second one? x will be 0 and you will find the value for y

Answer 24

im lost now

Answer 25

you have -2x -2y = -2 and x-3y=9. right?

Answer 26

oh wait lol

Answer 27

I thought it was another equation. Forget all of that.
You want to solve
x-y=1
x-3y=9

Just multiply the first or the second equation by -1.

Answer 28

wait so forget bout everything u said b4 now

Answer 29

Yep. Only consider my last post please

Answer 30

x-y=1 (A)
x-3y=9 (B)

multiply (A) by -1: -x+y=-1
Now sum it with (B)

Answer 31

okay well i figured it out its x = -3 and y = -4

Answer 32

can you help me with this one x- y= 2
x+y=6

Answer 33

Yup, that's correct. with this one you just have to do the same, actually it's easier because if you sum them you will find x

Answer 34

2x?

Answer 35

2x=8
now you have x=4
find y