U Rock If U Can Explain This Math Prob

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.

drgreen

Full Member
10+ Year Member
15+ Year Member
Joined
Feb 20, 2008
Messages
157
Reaction score
0
Photo224.jpg

THE ANSWER IS 5/47, but WHY?!
 
I don't know man! I get -2.9 what do you get?

This person is correct. Just plug in 5/47, its clearly not the answer.

first square both sides and you get: 10/ (x+3) = 100.
divide both sides by ten and you get 1/ (x+3) = 10 /1
cross multiply and get 10x + 30 = 1
subtract 30 and get 10x = -29
divide by ten and get x = -2.9

plug it in it works 🙂
 
I dont know where that question is from but i too am getting -2.9. Perhaps there is a mistake.
 
I get -2.9 as well. Not sure how or why it would be anything else. Sorry, guess I'm not the one to explain it -- unless the book answer is wrong somehow.
 
The answer is, without a doubt, -2.9.

You might look at this type of problem and freak out, but you shouldn't. Just take your time and solve for x.

The first thing you need to do is get rid of the square root. So square both sides of the equation. This leaves you with 2(5/x+3)=100.

Now get rid of the 2 by dividing both sides by 2. This gives you 5/x+3=50.

Now multiply both sides by (x+3). This gives you 5= 50(x+3).

Now get rid of the 50 by dividing both sides by 50. This gives 0.1=x+3

Now simply subtract 3 from both sides and you get -2.9=x

Hope this helps! Remember, you can do anything to these types of equations to simplify them as long as you do the exact same thing to both sides.
 
The way to solve is first to square each side. This gives you 2*(5/x+3)=100. Divide by 2 on both sides gives 5/(x+3)=50divide by 5 on each side and you get 1/(x+3)=10. Rearranging gives 1/10=x+3subtract 3 from both sides and x=-2.9
 
I take it the answer is -2.9 lol

I think i can see where they got that answer from... it's wrong, but the only explanation

square both sides:

2(5/x+3)=100

multiply both sides by 2:

5/x+3=50

Now they probably "subtracted 3 from each side" 😕 to foolishly get:

5/x=47
x=5/47

the only possible explanation. kaplan sucks
 
I take it the answer is -2.9 lol

I think i can see where they got that answer from... it's wrong, but the only explanation

square both sides:

2(5/x+3)=100

multiply both sides by 2:

5/x+3=50

Now they probably "subtracted 3 from each side" 😕 to foolishly get:

5/x=47
x=5/47

the only possible explanation. kaplan sucks

This is what I saw too...they probably rushed and effed it up by subtracting three and not treating (x+3) as a single term...

Good call though. Definitely -2.9
 
Top