Need help with math equation

Rebecca_V

Rebecca_V

Rookie
I really don't know where to post this so I chose this area. This problem is driving me nuts. I just cant remember how to solve it. Can anyone out there help me?

The equation I need solved is

8.65 = 3(r)^2

In case you don't know what ^2 means its r to the second power (root 2). Please if you know how to solve this please post the steps and answer. It's driving me insane.

Thanks!
The Good Rebecca
 
I'm not entirely sure but I think that you would:

divide 8.65 by 3 to get 2.8833,
then I would take the sqaure roots of both 2.8833 and r,
which would give you "r" on one side and a number on the other

I hope that is how you are supposed to do it, I had my math class last semester so I don't really remember very much.

Hope it helps!
 
This is with every possible step that you can take
8.65 = 3(r)^2 (the complete equation)
8.65 = 3*(r)^2 (the complete equation with the * inbetween 3 and (r)^2)
8.65 = 3*r^2 (the complete equation without the () )
8.65/3 = r^2 (12=3*4 equals: 12/3=4 --> 8.65=3*something equals 8.65/3=something)
2.88 = r^2 (8.65/3 = 2.88 --> 2.88 = something --> 2.88 = r^2)
r = squareroot 2.88 (if 2.88 is r^2 then using square root on 2.88 you get r)
r = 1.70 (after using square root you got the answer in this case)
piece of cake!

I just wonder why r is in between ()? That is useless with this equation. Only r displays another formula! But that isn't the case here!
 
Here is the orginal problem. I was attempting to short cut but hopefully this will help. I appreciate the responses so far by the way.

Determine the missing number in the sequence {3, ?, 8.65,...) Using the geometric formula y=a(b)^x. Hopefully this explanes it better. What I tried to do was take the x and y (Input and output) and the y-intercept. All I have to do is get the ratio. so I plugged in the formula
8.65 = 3(b)^2. The 8.65 is the output. The 3 is the y-intercept and the ^2 is the input.
so far I got 2.88 = (b)^2. I don't remember how to divide by a freakin' root.

I used the solved root from post above and I was able to get the second number in the sequence once I knew the ratio wa 1.70. I then took the input of one ratio of 1.70 and was able to solve for y. THANKS!!!

The Good Rebecca
 
I'm pretty sure I was taught it in grade 9, but I seem to remember doing those questions as early as grade 7.
 
I'm trying to get my bachelors degree in doing computional biology. On my entrance test they did not even show these kind of equations... Way to beginner level (their opinion). I am still wondering how I passed that damn test :lol:
 
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