1951 AHSME Problems/Problem 22
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Problem
The values of 
in the equation: $\log_{10}(a^2 \minus{} 15a) \equal{} 2$ (Error compiling LaTeX. Unknown error_msg) are:
$\textbf{(A)}\ \frac {15\pm\sqrt {233}}{2} \qquad\textbf{(B)}\ 20, \minus{} 5 \qquad\textbf{(C)}\ \frac {15 \pm \sqrt {305}}{2}$ (Error compiling LaTeX. Unknown error_msg)
Solution
Putting into exponential form, we get that 
Now we use the quadratic formula to solve for , and we get $a=\frac{15\pm\sqrt{625}}{2}\implies a=\boxed{\textbf{(B)}\ 20, \minus{} 5}$ (Error compiling LaTeX. Unknown error_msg)
See Also
| 1951 AHSC (Problems • Answer Key • Resources) | ||
| Preceded by Problem 21 |
Followed by Problem 23 | |
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| All AHSME Problems and Solutions | ||
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