Difference between revisions of "1990 AHSME Problems/Problem 1"
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Cross-multiplying leaves | Cross-multiplying leaves | ||
| − | <math><cmath> \begin{align*}\dfrac{x^2}{8} &= 8\\ x^2 &= 64\\ \sqrt{x} &= \sqrt{64}\\ x &= \pm 8\end{align*} </cmath></math> | + | <math><cmath> \begin{align*}\dfrac{x^2}{8} &= 8\\ x^2 &= 64\\ \sqrt{x^2} &= \sqrt{64}\\ x &= \pm 8\end{align*} </cmath></math> |
So the answer is <math>\boxed{\text{(E)} \, \pm 8}</math>. | So the answer is <math>\boxed{\text{(E)} \, \pm 8}</math>. | ||
{{MAA Notice}} | {{MAA Notice}} | ||
Revision as of 03:03, 4 November 2013
Problem
If 
, then 
Solution
Cross-multiplying leaves
$<cmath> \begin{align*}\dfrac{x^2}{8} &= 8\\ x^2 &= 64\\ \sqrt{x^2} &= \sqrt{64}\\ x &= \pm 8\end{align*} </cmath>$ (Error compiling LaTeX. Unknown error_msg)
So the answer is 
.
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. 
