Need major help with this algebra problem. Can you help please?

Question

Dan invests $3000 more in an account that pays 4% simple interest than he invests in an account that pays 3% simple interest. If the total interest earned for the first year is $610, how much did Dan invest in each account?

a. Let x represent the principal invested in the account paying 3% interest.
Let y represent what?
b. Write the two equations in terms of x and y.
c. Solve the system of equations and state the amount invested at 3% and at 4%.

Answer 1

Let x = the principal invested at 3% interest.
Let x+3000 = the principal invested at 4% interest.
So .03x +.04(x+3000) = 610
.03x + .04x + 120 = 610
.07x = 490
x = $7000 = amount at 3 %
x+3000 = $10,000 = amount at 4%
No need to have y. Just makes problem more difficult. Always take the easiest way.

Answer 2

i'm pretty sure this is right...
y is the amount invested in the 4% account
610=.03x + .04y
610=.03x + .04(x+3000)
610=.03x + .04x + 120
610+ .07x + 120
-120 -120
490= .07x
x= 7000 invested in 3% account
7000 + 3000 = 10000 in 4% account