I need this one with steps please

Question

A student takes out two loans totaling $8000 to help pay for college expenses. One loan is a 6% simple interest, and the other is at 5% simple interest. The first-year interest is $420. Find amount of the loan at 5%.

Answer 1

Why don't you give it a try, step by step? It's easy if you mentally divide the $8,000 into two parts:

x and 8,000-x.  Then use I = PRT (with T=1 yr) to calculate the interest for each one, and then add those expressions to set the total interest to $420.  I BELIEVE YOU CAN, AND SHOULD, DO THIS---and try to retain this basic type of approach to MANY word problems.

Answer 2

a + b = 8000 ------> a = 8000 - b

.06a + .05b = 420

 

Now, substitute...

 

.06(8000 - b) + .05b = 420

480 - .06b + .05b = 420

.01b = 60

b = 6000

 

$6000