I need need help with this linear equation

Question

A=P(1+rt) solve for r

 

My answer was(A-P)/Pt=r but my math teacher said that its wrong and I'm having trouble figuring out what it is

Answer 1

A=P(1+rt)

A=P+Prt

A-P=Prt

A-P=(Pt)r

(A-P)/(Pt)=r

you must enclose the Pt in parentheses

if not, (A-P)/Pt means (A-P)/P and then times t

for example...

20/4*5=(20/4)*5=5*5=25

20/(4*5)=20/20=1

the order of operations says multiply and divide in order from left to right whichever occurs first

the way you had it means divide (A-P) by P and then multiply the result by t

you want (A-P) to be divided by the product (Pt)

Answer 2

Do you know what the right answer is then? Why don't you just ask your teacher?