i = simple interest = 900 dolars p = principle = 1500 dollars r = interest rate = 0.03 (decimal form of 3%) t = time in years = unknown (leave it as t for now)
Plug in those values mentioned above and solve for t.
Simple interest formula i = p*r*t 900 = 1500*0.03*t 900 = 45*t 900/45 = 45*t/45 20 = t t = 20
Answer: 20 years
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Problem 17, part B
p = 1500 r = 0.03 t = 5 years
A = p+p*r*t A = 1500+1500*0.03*5 A = 1500+225 A = 1725
Answer: 1725 dollars
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Problem 17, part C
Factor out the GCF p, then divide both sides by 1+rt
A = p+p*r*t A = p*1+p*r*t A = p*(1+rt) A/(1+rt) = p*(1+rt)/(1+rt) A/(1+rt) = p p = A/(1+rt)
Answer: p = A/(1+rt)
The right side is the fraction of A all over the quantity (1+rt) which may be more readable if written like so [tex]p = \frac{A}{1+rt}[/tex] If you're going to write it in the way p = A/(1+rt) then don't forget to use parenthesis.
