## Expoential Growth: One hundred dollars is invested in 90 day

Quadratic equations and inequalities, variation equations, function notation, systems of equations, etc.
orange1998
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### Expoential Growth: One hundred dollars is invested in 90 day

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 PLEASE help me solve it. Thanks!

Oh, and if/when you do solve this, EXPLAIN? Thanks, cause, I've got 5 more just like this one to solve.

maggiemagnet
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### Re: Expoential Growth: One hundred dollars is invested in 90

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.
What is the value of b? Where is the "rate" in your equation?
Oh, and if/when you do solve this, EXPLAIN?
There's an explanation of exponential growth here.

orange1998
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Joined: Tue Mar 27, 2012 5:51 am
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### Re: Expoential Growth: One hundred dollars is invested in 90

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.

orange1998
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Joined: Tue Mar 27, 2012 5:51 am
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### Re: Expoential Growth: One hundred dollars is invested in 90

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

maggiemagnet
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### Re: Expoential Growth: One hundred dollars is invested in 90

Okay, if you're supposed to use that equation, then solve for the value of "b". Then interpret this value according to whatever formula they gave you.

orange1998
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Joined: Tue Mar 27, 2012 5:51 am
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### Re: Expoential Growth: One hundred dollars is invested in 90

Thanks, I figured it out.