Find the simple interest earned to the nearest cent for each principal, interest rate, and time. PLS HELP

for the first one its I=38.40  for the 2nd one its $315

Step-by-step explanation:

Simple interest , I, is calculated by multiplying the principal, P, by the rate,r, by the time, t, in years:

I = P * r * t

Here, P = $640

r = 0.03   (decimal value for 3%)

t  = 2 years

The interest will be:  

I = P * r * t

I = 640 * 0.03 * 2

I = $38.40

2nd one:

We know, Interest value = P * R * T /100

Here, P = 1500

R = 4.25

T = 4

Substitute their values,

I = 1500 * 5.25 * 4 / 100

I = 31500 / 100

I = 315

In short, Your Final Answer would be $315

3rd

assuming you subtract 2% of 580 a month for six months. your remaining money would be $510.40

because you subtract $69.6 from 580

4th

$1231

Step-by-step explanation:

Given,

Principal amount = $1200

Rate of interest = 3.9%

Time = 8 months or (8/12) 0.666667 years

Formula of simple interest =

A = 1200(1+(0.039 × 0.666667))

A = 1200 (1+0.026)

A = 1200 (1.026)

A = $1231

Please give brainliest!!