Heather compares the price of a new computer at two different stores. Store $A$ offers $15\%$ off the sticker price followed by a $$90$ rebate, and store $B$ offers $25\%$ off the same sticker price with no rebate. Heather saves $$15$ by buying the computer at store $A$ instead of store $B$. What is the sticker price of the computer, in dollars?
$\mathrm{(A)}\ 750\qquad\mathrm{(B)}\ 900\qquad\mathrm{(C)}\ 1000\qquad\mathrm{(D)}\ 1050\qquad\mathrm{(E)}\ 1500$
Solution 1
Let the sticker price be $x$.
The price of the computer is $0.85x-90$ at store $A$ and $0.75x$ at store $B$.
Heather saves $$15$ at store $A$, so $0.85x-90+15=0.75x$.
Solving, we find $x=750$, and thus the answer is $\mathrm{(A)}$.

Solution 2
The $$ 90$ at store $A$ is $$ 15$ greater than the additional $25\%-15\% = 10\%$ off at store $B$.
Thus the $10\%$ off is equal to $$ 90$ $-$ $$ 15$ $=$ $$ 75$, and therefore the sticker price is $$ 750$.