Question

y = 8x − 9
y = 4x − 1

Part A: Explain how you will solve the pair of equations by substitution or elimination. Show all the steps and write the solution.

Part B: If the two equations are graphed, at what point will the lines representing the two equations intersect? Explain your answer.

Answer 1

what is a variable that u can eliminate?

Answer 2

X? I think. I'm completely lost

Answer 3

treat this as an equation

Answer 4

You can add or subtract to eliminate a letter (x or y).

Answer 5

\[\frac{ y=8x-9 } { y=4x-1 }\]

Answer 6

so can you see any thing that can be eliminated by subtraction or addition?

Answer 7

hello??

Answer 8

9-1??? Sorry I didn't reply I got sidetracked

Answer 9

do u know wit a variable is?

Answer 10

@andrea0529

Answer 11

I'm sorry I really need help I suck at math pls

Answer 12

For part B, we graph these two equations y=8x-9 and y= 4x-1
then the point of intersection is when there is a solution for both of these equations

Answer 13

For part A. substitution is a better choice.

Answer 14

u can eliminate y

Answer 15

so it becomes \[\frac{ 8x-9 }{ 4x-1 }\]

Answer 16

Why would you say that I came on here for help because I care about my education not to be insulted by rude people like you.

Answer 17

and how the heck can you solve with that?

Answer 18

anyway set these two equations together
8x-9 = 4x-1
put all variables to the left and all numbers to the right
8x-4x=-1+9

now what's 8x-4x and what's -1+9 ?

Answer 19

Fine I don't want your help. You didn't hack me shut up.

Answer 20

-_- ughhhh @ganeshie8

Answer 21

@Icedragon50 stop creating drama on here. Just leave if you can't help nicely to other OS users.

Answer 22

Thank you @usukidoll for actually helping me

Answer 23

\[8x-y=9\]\[4x-y=1\]

Answer 24

looking it this way might help

Answer 25

@saseal that works too

elimination or substitution can give the same results.

Answer 26

-1+9=8 thanks so much

Answer 27

forgot one part though
8x-4x=-1+9

now what's 8x-4x and what's -1+9 ?

what's 8x-4x ?

Answer 28

yea its easier to put in matrix form that way :)

Answer 29

true, but most of the time , matrix form versions are taught way later o_O.

Answer 30

@andrea0529 what's 8x-4x ?
or an easier way to put it by factoring the x
x(8-4) what's 8-4 ?

Answer 31

4x

Answer 32

yea, once you go matrix you dont go back!

Answer 33

:)
so now we have 4x = 8
we divide 4 from both sides
so what's 8/4 ?

Answer 34

8 divided by 4 @andrea0529
then we have x by itself after that step.