## anonymous one year ago help Which equation does the graph of the systems of equations solve? 2 linear graphs. They intersect at 0,3

1. anonymous

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

2. zepdrix

Notice that they intersect at an x coordinate of 0.

3. zepdrix

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.

4. zepdrix

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

5. anonymous

yes let me try

6. zepdrix

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.

7. anonymous

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

8. zepdrix

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.

9. anonymous

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

10. anonymous

it would be option D

11. zepdrix

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! :)

12. anonymous

yes that's correct, thank you very much