Answer:
=
−
8
Step-by-step explanation:
Combine like terms
Divide both sides of the equation by the same term
Simplify
Step-by-step explanation:
Recall that

Therefore,

so


Since 7 is greater than 5, you input it into the last equation.
2•(7) -7
14-7
7
The answer is 7!
Answer:
If P= price of the hardcover book, then
We have to spend $25-P, if P<$25; or $0 if P>= $25
Step-by-step explanation:
Lets call P the price of the hardcover book, in $. We can suppose that P is less than 25, otherwise we shoudnt spend on anything else to get the free shipping. If X is the amount that we have to spend to reach 25, then we get that P+X = 25. If P is known, we can obtain X by substracting P in both sides, therefore
X = 25-P
We conclude that if the price of the book P is less than 25, then we have to spend $25-P. Otherwise we have to spend 0.
For perimeter you add all of the sides but for area you multiply each side