0.07x+0.08 (9000-x)=700
Solve for x
0.07x+720-0.08x=700
0.07x-0.08x=700-720
-0.01x=-20
X=20÷0.01
X=2,000 invested at 7%
9000-2000=7000 invested at 8%
404,991
PEMDAS
Multiplication comes before subtraction
900x450=405,000
405,000-9=404,991
Your answer is C If not A have a good day
The equation for the direct variation is y= kx (where k is contant of variation.)
This equation represent that if x will increase then y will also increase because it's k times x.
Where the equation for indirect variation is 
By this equation if x will increase then y will decrease and vice versa.
The given data is :
x: 2 4 8 12
y: 4 2 1 2/3
Notice as x is increasing then y is decreasing. Like x has increased from 2 to 4 then y is decresing from 4 to 2 and so on.
So, the given data represent an indirect variation.