Math Help????

Question

Write the formula to compute the missing value. DO Not Solve.??
1) principe=$100
rate=4%
time=2years
interest=?


2) principal=$150
rate=?
time=2 years
intrest=$9

3) principal=$200
rate 5%
time=?
intrest= $10

4) principal=?
rate=3%
time=4 years
interest= 30


help please

Answer 1

I RESPECT YOU.

Simple Interest:
I = PRT
I = interest
P=Principle
R = Rates(%){Interest/Principal*100}
T = Time
In order to find everything, then find either P, R or T individually.

Compound Interest: i.e. most loaning from banks

A=P(1+i)^n

(note: i is NOT the equivalent of SQRT(-1))
P, is the same
A= is the end compounded principle
i is the Interest
n = time

Answer 2

1) interest= Principal * Rate * Time */100

Answer 3

For simple interest,
I = nP(1 + r)
n = I/(P(1 + r)
P = I/(n(1 + r)
r = (I - nP)/(nP)

For compound interest,
I = P((1 + r)^n - 1)
P = I/((1 + r)^n - 1)
n = (log(1 + I/P))/log(1 + r)
r = (1 + I/P)^(1/n) - 1

Answer 4

1. y=200(1+0.04)^2

2. y=150(1+?)^10

3. y=200(1+0.05)^?

4. y=?(1+0.03)^4