To start, let x represent the cost of the mutual fund that earned 9%.
This cost will be represented by the term 0.09x.
Now, let (1200-x) represent the cost of the mutual fund that earned 3% profit, since the two amounts must add up to be 1200, the amount the investor originally invested.
This cost will be represented by 0.03(1200-x)
Next, because the overall profit of the two mutual funds earned was 78 dollars, you can set up this equation: 0.09x+0.03(1200-x)=78
Now, solve for the value of x: 0.09x+0.03(1200-x)=78 0.09x+36-0.03x=78 0.06x+36=78 0.06x=42 x=700
Therefore, the amount invested in the 9% mutual fund would be $700 dollars.
follow a few exponent rules and you can figure this out
when expoenents are to the power of something you can mutilply the expoents.. and when there is a minus sign in the exponent.. it's like the reciprocal is 1/ soooo...
mutilply the -2/3 by each of the exponents in the question the 8 is tricky b/c it has an invisible 1 on it :o