How much money was invested at 5% annual simple interest for 4 years to earn $2870?

Principal (amount invested) = $14,350

Step-by-step explanation:

Given the simple interest amount of $2,870 earned in 4 years at 5% interest rate:

In order to find the principal amount that was invested, we could use the simple interest formula and isolate the variable, P, algebraically.

I = P × r × t

where:

I = interest earned = $2,870

P  = principal amount invested = ?

r  = interest rate = 5% or 0.05

t = time = 4

Divide both sides by (r × t ) to isolate P :

Substitute the given values into the formula for P:

Therefore, the principal amount invested is $14,350.

investment b is an ordinary annuity with $3,909.64 in the account after one year.

step-by-step explanation:

3

step-by-step explanation:

because where the point where the 2 lines intersect is (3,-1) the x value is 3