After 2.5 years your investment account has earned $450 in interest. If the interest rate is 7.5% what was the principle on your account?

$2400

Step-by-step explanation:

Given

Interest earned is $450

The rate of interest is R=7.5%

Time period T=2.5 years

Simple Interest is given by

Substitute values

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116