eviant:

PLS HELP!!! QS is the perpendicular bisector of PR . Solve for x. https://dlap.gradpoint.com/Resz/~yUA6AAAAAAQzi_EEDSiPwA.-c1n8jFGR2INWft2KDocAD/7234256,F04/Assets/questions/quiz/geometry/geoconst/geoconst-g-17.png

8 months ago
iGreen:

Well? What's the relationship between PS and SR?

8 months ago
eviant:

they're collinear?

8 months ago
iGreen:

They're the same. QS bisects PR, which means PS and SR must be the same. Based on that, what can we do to solve for 'x'?

8 months ago
BenLindquist:

green, are you good at geometry/cal?

8 months ago
eviant:

I don't get it

8 months ago
eviant:

do we need to make them equal, and solve?

8 months ago
iGreen:

QS bisects PR. That means that PS and SR have to be equal to each other, since bisect means to divide equally in half. PS is 2x - 20 SR is 70 - x We can set these two equal to each other.

8 months ago
iGreen:

@BenLindquist Uh, what's your problem? It's been a year since I've taken Calculus, dunno how much of it I'd remember.

8 months ago
BenLindquist:

I might need help with geometry mostly. I have cal as an elective

8 months ago
iGreen:

It all depends on the question.

8 months ago
iGreen:

Anyway, @eviant can you set those two equal to each other and solve?

8 months ago
eviant:

50?

8 months ago
eviant:

is what i came up with

8 months ago
iGreen:

Not quite, try again. You can do it step-by-step here if you want.

8 months ago
eviant:

I have to subtract 20 from both sides

8 months ago
iGreen:

Wait no, it's being subtracted. So we have to do the opposite.

8 months ago
eviant:

so, add

8 months ago
iGreen:

\(\sf 2x - 20 = 70 - x\) Yes

8 months ago
iGreen:

What are you left with?

8 months ago
eviant:

so, it'd be 2x-40=70-20x?

8 months ago
iGreen:

What? No...add 20 to both sides: \(\sf 2x-20\color{red}{+20}=70-x\color{red}{+20}\)

8 months ago
eviant:

now, subtract,?

8 months ago
eviant:

or divide?

8 months ago
iGreen:

Simplify it... -20 + 20 = ? 70 + 20 = ?

8 months ago
eviant:

90

8 months ago
eviant:

and 0

8 months ago
iGreen:

Yes..so we're left with: \(\sf 2x=90-x\) Now what do we do?

8 months ago
eviant:

divide, so the answer is 45?

8 months ago
iGreen:

No, we still have to get rid of that other 'x'...what do we do to it?

8 months ago
eviant:

subtract it?

8 months ago
iGreen:

It's being subtracted from the 90. We have to do the opposite.

8 months ago
eviant:

so, add it, 90+x

8 months ago
iGreen:

Add it to both sides. The whole point is to get rid of the 'x' on the right side. \(\sf 2x\color{red}{+x}=90-x\color{red}{+x}\)

8 months ago
iGreen:

2x + x = ? -x + x = ?

8 months ago
eviant:

3x?

8 months ago
iGreen:

Yes, and...?

8 months ago
eviant:

90 divide by 3=30?

8 months ago
eviant:

so, 30 is the answer?

8 months ago
iGreen:

Yep, you got it.

8 months ago