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cutie.patootie
More help? Type the equation of the given line in standard form. The line with m = 4 and intersecting 2x -4y = 8 at x = 6. Thanks!
Step #1: convert "2x -4y = 8" to y=mx+b Step #2...
So that would make it -4y=2x+8?
Or do I have to put the m in there to and make it -4y=8x+8?
you want y not -4y so you should simplify
Move the 2x over to the other side (with subtraction), divide both sides by -4. Can you write this second step @cutie.patootie ? :-) You'll end up getting a y=mx+b form line that allows to to draw this: |dw:1343071328047:dw|
-4y=2x+8 turns into.. -4y-2x=8 divide by -4 gives you.. y+(1/2)x=2 Right?
No... unless you wrote it incorrect at the start. -4y + 2x = 8? Move the x's over -4y = -2x + 8 Divide by -4 y = 0.5 x - 2 (see graph above)
Oh well I had it right, but then I moved the x to the wrong side. But I see where I made my mistake now.
then it tells you there is some other line with: y = 4x + b , because it says "m = 4" An "intersection of two lines" means when they are equal to each other. If you've solved both for the dependent varible (y) that means you can set the y's equal to each other: \(y_1 = y_2\) we know: \(y_1 = \frac{1}{2}x - 2\) \(y_2 = 4x + b_2\) So... \(y_1 = y_2\) \(\frac{1}{2}x - 2 = 4x + b_2\) Make sense? The final steps are substitute in "x=6", solve for \(b_2\), and rewrite \(y_2\)
Okay, so you get... (1/2)(6) - 2 = 4(6) +b2 3-2=24+b2 1=24+b2 b2= -23?
You're correct! |dw:1343072679957:dw|
When x = 6, they are both equal.
Now don't forget to rewrite \(y_2=4x-23\) in standard form :-) All good?
Okay, I think I follow. So I write it y + 4x = -23?
And yes! Hahaha.