Question

Consider the following pair of equations:

y = x + 4
y = –2x – 2

Explain how you will solve the pair of equations by substitution. Show all the steps and write the solution in (x, y) form.

Answer 1

I will give medal to the person that answers

Answer 2

Please Help me

Answer 3

Okay. Lets see here. What do you mean by substitution?

Answer 4

U have to somehow substitute into the second equation

Answer 5

okay....

Answer 6

I think like this y= -2(x+4) -2

Answer 7

Okay. So... we need to find X. Lets make a balanced equation. y+2=-2x-8. y+10=-2x

Answer 8

will that help?

Answer 9

I just dont get what to do next

Answer 10

like the steps to finding the answer

Answer 11

What Do i do next?

Answer 12

Someone Please Help will give medal!

Answer 13

Okay let's try this
A) y = x + 4
B) y = –2x – 2

Let's put equation A into B

x+4 = –2x – 2

3x = -6

x = ?

Answer 14

= -2?

Answer 15

Yes that's right.

Answer 16

Okay now I plug that in the first one right?

Answer 17

y = -2 + 4 ?

Answer 18

So the solution is (2, -2)

Answer 19

I havent seen how u got the 3x= -6 can u show me?

Answer 20

x = -2 and y = 2 so you would write the solutions as you would an (x,y) point
or (-2, 2)

Answer 21

Okay I'll just recopy the answer I previously gave:

A) y = x + 4
B) y = –2x – 2

Let's put equation A into B

x+4 = –2x – 2

3x = -6

x = ?

Answer 22

Yes I just dont get how u got 3x= -6

Answer 23

You do see how equation A goes into B right?

Answer 24

yes

Answer 25

but then how did u turn it to 3x = -6

Answer 26

Okay here's equation A into equation B
x+4 = –2x – 2

Answer 27

Okay and what u did next to get 3x = -6

Answer 28

Add 2x to both sides of the equation

Answer 29

Like this
x + 4 = -2x -2
+2x +2x

Answer 30

No, like this
x+4 = –2x – 2
now adding 2x to both sides
x+4 +2x = –2x – 2 +2x
Can you simplify that?

Answer 31

okay 4 + 2 = 6 and -2+ 2= 0

Answer 32

No, you have to add or subtract the x terms
x+4 +2x = –2x – 2 +2x

3x + 4 = -2x + 2x -2

3x + 4 = -2

You follow that?

Answer 33

okay got that so now we have 3x + 4 = -2

Answer 34

3x + 4 = -2
-4 -4
= 3x = -6

Answer 35

3x + 4 = -2

Now we add -4 to both sides
3x + 4 -4 = -2 -4

Can you simplify that?

Answer 36

yes 3x = -6

Answer 37

Thank you very much!

Answer 38

u r welcome :-)