What does the 7-5 mean at the end?
Answer:
Hence the expression 
Step-by-step explanation:
Explanation
- The given expression is (3rs-7)(3rs-4).
- We have to multiply the given expression.
- Multiply the (3rs-7) by -4, multiply the (3rs-7) by 3rs then add like terms.

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The total charges for the first club as a function of the number of rentals (x) are
... f1 = 25 + 2.50x
The total charges for the second club are
... f2 = 3.25x
We want to find x so that f1 < f2.
... f1 < f2
... 25 + 2.50x < 3.25x
.. 25 < 0.75x . . . . . . . . . . subtract 2.50x
... 25/0.75 < x . . . . . . . . . divide by the coefficient of x
... 33 1/3 < x
You must rent 34 videos or more to make the first club more economical.
1144 Liters of oil.
For every 5 there is 8 used. So 440/5 = 88. 88 units times 8 is 704. 704 synthetic plus 440 natural is 1144 liters of oil total.