- Thu Apr 05, 2012 2:54 am
- Forum: Intermediate Algebra
- Topic: Exponential decay, growth: radioactive element, petri dish
- Replies:
**1** - Views:
**2296**

A radioactive element has a count of 120. Four weeks later, the count is 104. Find the daily rate of decay. Another one I need help with... A petri dish contains a bacteria count of 6000. Two days ago, the count was 9720. What will the count be 5 days from now if the daily rate remains the same?? I ...

- Thu Apr 05, 2012 2:52 am
- Forum: Intermediate Algebra
- Topic: Expoential Growth: One hundred dollars is invested in 90 day
- Replies:
**5** - Views:
**2127**

Thanks, I figured it out.

- Sun Apr 01, 2012 5:02 pm
- Forum: Beginning Algebra
- Topic: Exponents: (3^2x)(9^x), (a^2)^b (a^b)^2, a^-4/b^-4
- Replies:
**3** - Views:
**1932**

What do you mean try turning everything into power on 3? I'm confused on that one.. The rest still make sense and I'm good on, thanks.

- Sat Mar 31, 2012 5:40 pm
- Forum: Intermediate Algebra
- Topic: Expoential Growth: One hundred dollars is invested in 90 day
- Replies:
**5** - Views:
**2127**

The thing is is that they're teaching me stuff with all those different equations, my teacher taught us y=a*b^x and says we should be able to use that to figure out this problem. I'm SUPER confused. Lol

- Sat Mar 31, 2012 5:18 pm
- Forum: Intermediate Algebra
- Topic: Expoential Growth: One hundred dollars is invested in 90 day
- Replies:
**5** - Views:
**2127**

Yeahh, the value of "b" is the rate change, that's what I'm having trouble figuring out. That's what we are looking for.. Thanks for the link.

- Fri Mar 30, 2012 10:42 pm
- Forum: Beginning Algebra
- Topic: Exponents: (3^2x)(9^x), (a^2)^b (a^b)^2, a^-4/b^-4
- Replies:
**3** - Views:
**1932**

(3^2x)(9^x)= ?

Does it, or does it not, equal 27^3x

Another...

(a^2)^b (a^b)^2 = a^4b Correct?

Also..

a^-4/b^-4 = (b/a)^-4 That's incorrect, right? Shouldn't it be (b/a)^4 a positive exponent, not a negative?

Thanksssssssss(:

Does it, or does it not, equal 27^3x

Another...

(a^2)^b (a^b)^2 = a^4b Correct?

Also..

a^-4/b^-4 = (b/a)^-4 That's incorrect, right? Shouldn't it be (b/a)^4 a positive exponent, not a negative?

Thanksssssssss(:

- Fri Mar 30, 2012 10:40 pm
- Forum: Intermediate Algebra
- Topic: Expoential Growth: One hundred dollars is invested in 90 day
- Replies:
**5** - Views:
**2127**

One hundred dollars is invested in 90 days. At the end of the term, the investment is worth $120. Find the growth rate per day. I do NOT get this... My equation was; 120=100 times b^90. Using the formula y= a times b^x Is that equation right, and how do I solve it? Even if it's not right, just PLEAS...