Solving Algebra Word Equation

Question

Nico is saving money for his college education. He invests some money at 7​%, and $1500 less than that amount at 4%.The investments produced a total of ​$204 interest in 1 yr. How much did he invest at each​ rate?

Answer 1

Let x = amount at 7%

x-1500 = amount at 4%

x(.07) + (x-1500)(.04) = 204

multiply through by 100

7x +4x -6000= 20400

11x = 26400

x = 26400/11 = 2400 at 7%

x-1500 = 900 at 4%