You have already invested $600 in a stock with an annual return of 11%. How much of an additional $1,200 should be invested at 12% and how much at 6% so that the total return on the entire $1,800 is 9%? (Round each answer to the nearest cent.)

Question

istim · Answer

So, what have you done so far?

rogue · Answer

600 * 0.11 = $66
1800 * 0.09 = $162
The return from the 1200 should be 162 - 66 = $96

x + y = 1200
.12x + .6y = 162

Solve the system.

rogue · Answer

Can you do that?

rogue · Answer

oops, 
.12x + .6y = 96, not 162

anonymous · Answer

so from there i just solve for Y and that's my answer?

rogue · Answer

After you solve for y, use that to solve for x as well. y is the amount that is going to be invested at 6%, x is invested at 12%

anonymous · Answer

wait now im lost haha

rogue · Answer

x + y = 1200
.12x + .06y = 96

x = 1200 - y ------> .12x + 0.06y = 96
.12(1200 - y) + 0.06y = 96
144 - .12y + 0.06y = 96
48 = 0.06y
y = 800

x + y = 1200
x + 800 = 1200
x = 400

rogue · Answer

Sorry, I made a mistake (twice :/) originally when I posted the system. I put 0.6y instead of 0.06y.