Nico is saving money for his college education. he invests some money at 9% and $1400 less than that amount at 3%. the investments produced a total of $198 interest in 1 yr. how much did he invest at each rate?

Let x = the amount of money he invests at 9%
and y = the amount of money he invests at 3%

y = x - 1400
0.09x + 0.03y = 198

x - y = 1400
9x + 3y = 19800

3x - 3y = 4200
9x + 3y = 19800

12x = 24000
x = 2000
y = 600

$2000 invested at 9% interest
and $600 invested at 3% interest.

1. isolate the variable, in this case, d. subtract 35.5 on both sides of the equation.2. 52 subtracted by 35.5 is 16.53. therefore your answer would be d= 16.5this is the basics of pre algebra, isolating variable through adding, subtracting, multiplying, and dividing, if you have any other questions to ask just comment!