-9(x+8)+81=13-10x what does x equal?
2 answers:
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Answer:
Step-by-step explanation:
We know a total of 6000 is being turned into 510, in two accounts which equal to 15%, to find how much is in each account we can create the following equation:
Solve for x
Now multiply x by the corresponding percentages to find how much was invested into each percentage.
Therefore we now know that 170 dollars was invested into the 5% division, and 340 dollars was invested into the 10% division.
We can of course check our answer by adding 170+340 which equals our original investment of 510.
Answer:
- Hayes family: 35 hours
- Rodrigues family: 40 hours
Step-by-step explanation:
Let x and y represent the usage hours by the Hayes and Rodrigues families, respectively. The problem statement gives us relations that can be used to write equations for volume of use and for total hours.
15x +30y = 1725 . . . . . total liters of use
x + y = 75 . . . . . . . . . total hours of use
The second equation lets us write an expression for y:
y = 75 -x
This can be substituted into the first equation to give ...
15x +30(75 -x) = 1725
-15x + 2250 = 1725 . . . . . . simplify
-15x = -525 . . . . . . . . . . . subtract 2250
x = 35 . . . . . . . . . . . . . . divide by -15
y = 75 -35 = 40
The Hayes family used their sprinklers for 35 hours; the Rodrigues family used theirs for 40 hours.
