50 POINTS ILL GIVE BRAINLIEST ! random answers will be reported! Find the principal of interest!!
1. Interest: $640
Rate: 4%
Time: 1 year
2. Interest: $2,016
Rate: 12%
Time: 3 years

4)P = $615.38.   5)P = $1,482.35

Step-by-step explanation:

4)P = $615.38

Equation:

P = A / (1 + rt)

Calculation:

First, converting R percent to r a decimal

r = R/100 = 4%/100 = 0.04 per year.

Solving our equation:

P = 640 / ( 1 + (0.04 × 1)) = 615.38461538462

P = $615.38

The principal investment required to get a total amount, principal plus interest, of $640.00 from simple interest at a rate of 4% per year for 1 years is $615.38.

2)P = $1,482.35

Equation:

P = A / (1 + rt)

Calculation:

First, converting R percent to r a decimal

r = R/100 = 12%/100 = 0.12 per year.

Solving our equation:

P = 2016 / ( 1 + (0.12 × 3)) = 1482.3529411765

P = $1,482.35

The principal investment required to get a total amount, principal plus interest, of $2,016.00 from simple interest at a rate of 12% per year for 3 years is $1,482.35.