Question

help
Which equation does the graph of the systems of equations solve?

2 linear graphs. They intersect at 0,3

Answer 1

Answer choices
A) −2x + 3 = 8x − 3
B) −2x + 4 = −8x + 4
C) 2x + 4 = 8x − 4
D) 2x + 3 = −8x + 3

Answer 2

Notice that they intersect at an x coordinate of 0.

Answer 3

Let's look at option A.
-2x + 3 = 8x - 3
`I'll add 2x to each side`
3 = 10x - 3
`I'll add 3 to each side`
6 = 10x

Hmm this is NOT going to lead to a solution of x=0, which is what we want.

Answer 4

Do you think you can try the other options? :o
Solve for x in each case.

Answer 5

yes let me try

Answer 6

Oh that was a sloppy method of doing that actually :\
That's going to only narrow it down to two options.

I guess a better way to do it would be...
plug in x=0,
and see which equation gives you 3 = 3.

Answer 7

okay let me try doing it that way
can you show me an example please

Answer 8

For Option A,
\(\large\rm -2x + 3 = 8x - 3\)
We know that the point of intersection is at (0,3), so I'll plug in this x coordinate of 0, and it should give us 3 as a result on both sides,
\(\large\rm -2(0)+3=8(0)-3\)
Which simplifies to
\(\large\rm 0+3=0-3\)
And since \(\large\rm 3\ne-3\), this is not the correct option for us.

Answer 9

okay I'll try it for the other options, give me few seconds please
thank you

Answer 10

it would be option D

Answer 11

Yay good job \c:/

Notice that using the first method I explained..
Would have given you option B as a correct choice, so that was no beuno.
This worked out much better! :)

Answer 12

yes that's correct, thank you very much