Answer:
900 at 12%
2100 at 10%
Step-by-step explanation:
Let x= amount invested at 12%
let y= amount invested at 10%
with that being said we can write the two equation
Equation 1: x+y=3000
Equation 2: 3000*.106=.12x+.1y
isolte x from equation 1
x= 3000-y
plug this into equation 2
318=.12(3000-y)+.1y
318=360-.12y+.1y
-42= -.02y
y= 2100
Plug this into equation 1
x+2100=3000
x=900