Question 888513
B/1 + rt = P 

I will assume that the formula is B/(1 + rt) = p.

Now it makes sense.

Multiply both sides by the denominator of the fraction.

After doing that, we get

B = p(1 + rt)

Distribute p on the right side to remove parentheses.

B = p + prt

Subtract p from B.

B - p = prt

Divide bot sides by pt.

(B - p)/pt = r

Done!