PLEASE HELP ALGEBRA

Question

Trey borrowed a total of $3000

 from two student loans. One loan charged 3%

 simple interest and the other charged 2.5%

 simple interest, both payable after graduation. If the interest he owed after 4

 years was $310

, determine the amount of principal for each loan.

Answer 1

i = p * r* t

0.025x(4) + 0.03(3000 - x)(4) = 310

0.025x + 0.03(3000 - x) = 77.5

0.025x + 90 - 0.03x = 77.5

-0.005x = -125

x = 2500