<span>d. y = 15x 900</span>
Although you do not give the rates I assume the answer is D as it is the only positive multiplication. You cannot have negative height.
X - <span>the cost of cell phone service before tax is added
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The answer is c
12.4 feet by 9.5 feet
I'm not sure what your statement is.
Is it x+y = 10?
Because if it is, the negation of this statement would simply be x+y<span>≠10, which stands for not equal. </span>