2007 AMC 10B Problems/Problem 2
Contents
Problem
Define the operation by
What is
Solution 1
Substitute and simplify.
Solution 2
Note that $\begin{align*} (a \star b) - (b \star a) &= (a+b)b - (b+a)a \\ &= (a+b)(b-a) \\ &= b^2 - a^2 \\ &= 5^2 - 3^2 = \boxed{\textbf{(E) }16}$ (Error compiling LaTeX. Unknown error_msg)
See Also
2007 AMC 10B (Problems • Answer Key • Resources) | ||
Preceded by Problem 1 |
Followed by Problem 3 | |
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