Question

Help me with three questions??? I don't understand this??

Answer 1

5. Find the solution to the system of equations by using either graphing or substitution.
y = 6 – x and y = x – 2 (1 point)
(2, 4)
(–4, 2)
(4, 2)
no solutions
6. y = 2x – 1 and y = x + 3 (1 point)
(4, 7)
(7, 4)
(–7, –4)
infinite solutions
7. y = 4x and y + x = 5 (1 point)
(–4, 1)
(1, 4)
(–3, 2)
(2, 3)

Answer 2

I don't understand how to do this

Answer 3

tell me if you don't understand anything, else do the same thing on each one.

Answer 4

Thank you so much!!!

Answer 5

y = 6-x
y = x-2
this last one implies x = y+2 now plug that into the first one
y = 6 - (y+2)
y = 6 - y - 2
simplify
2y = 4
y = 2
now plug y into either equation
2 = 6 - x
x = 4
so (4,2)

Answer 6

So for the second one I have to plug in x+3
so it will be y = 2x – 1(x+2)

Answer 7

I mean y = 2x – 1(x+3)

Answer 8

how do I simplify it?

Answer 9

y = 2x-1
y = x+3
the last one imples x = y - 3
plug that into the first
y = 2*(y-3) - 1

Answer 10

notice
y = 2* something - 1
x is that something
we use y = x+3 to write x = y - 3
so our something is y -3
so 2*something - 1 = 2(y-3) - 1

Answer 11

now we have y = 2(y-3) - 1

Answer 12

you explain this so much better than my teacher Thanks!!!

Answer 13

np: now solve for 2(y-3) - 1 = y
2y - 6 - 1 = y
y = 7
so since y = x+3
7 = x+3
so x = 4
so (4,7)

Answer 14

so for the third one it is y = 4x(y + x = 5)

Answer 15

y = 4x and y + x = 5
pick the second equation and tell me what x =

Answer 16

better yet

Answer 17

on the second equation we have
y + x = 5
according to the 1st equation what is y = ?

Answer 18

4x

Answer 19

so put that where ever you see a y in the second equation and tell me what that looks like

Answer 20

4x+4=5

Answer 21

why 4x + 4?

Answer 22

argh i mean 4x+x=5

Answer 23

right

Answer 24

so what is x?

Answer 25

what is 4x+1x?

Answer 26

5

Answer 27

so x=1

Answer 28

let x = apples
if you have 4 apples and I give you another apples what do you have?

Answer 29

5 apples

Answer 30

4x+x = 5
5x = 5
x = 1

Answer 31

yes

Answer 32

you said 5 I think you meant 5x

Answer 33

yes!!

Answer 34

ok so if x = 1, what is y?

Answer 35

pick either equation

Answer 36

i mean 4x

Answer 37

so what is y if x is 1?

Answer 38

so I'm using the second equation 1+3=4?

Answer 39

does that mean the answer is B (1, 4)?

Answer 40

you can use either equation they will tell you the same thing
equation 1
y = 4x
x = 1 so y = 4*x --> y = 4*1 --> y = 4

Answer 41

second equation
y + x = 5
x = 1
so y + 1 = 5
so y = 4

Answer 42

after you solve for one of the variables using substitution you plug that value into either of your starting equations and solve for the other variable.

Answer 43

Thank you so much I wish you were my teacher instead of the one I have right now!!

Answer 44

example
4+x = y
3y = 6

now
since y = 4 + x
3y=6 --> 3*(4+x) = 6
we solve for x
12+3x = 6
3x = -6
x = -2
now we know what x is
so now pick the easier equation to figure out what y is
y = 4+x
and we know x = -2
so y = 4-2
y =2
so
(-2,2)

Answer 45

Thank you I get it now!!! Thanks for you time and for teaching me this.

Answer 46

this was a silly example and could be done a much easier way but I wanted to give you a basic case.

Answer 47

ok good luck