Question

Michael borrows money from his uncle, who is charging him simple interest using the formula I=prt. to figure out what the interest rate,r,is, Michael rearranges the formula to find r his new formula is r equals

Answer 1

`(I)/(Pt)`= r

Explanation:

First write down the equation they gave you:

l = Prt

You need to ask yourself what is being done to r. r in this case is being multiplied by two variable: P and t. To undo multiplication you divide, the set up for division:

`(I)/(Pt) = (Prt)/(Pt)`

I divided by the two numbers, so it would be easier. The P and T cancels out on the right and you are left with r. On the left, however, it stays the same because there are no like terms to solve with. You just leave
`(I)/(Pt)` as it is.

The result you get is:

`(I)/(Pt)=r`

Answer 2

Since the original is Interest equals price times rate times time, taking out rate still includes price times time. So, you first have R = pt. Now to insert interest, you would have to divide the interest by pt, since you invert the multiplying of Rate. So, it would be R = I/pt. Basically, this is used for finding any of the prt segment. For P, use P= I/rt. For T, use T = I/pr. And for Michael's case, to find Rate you use R = I/pt.