Difference between revisions of "2007 AMC 10B Problems/Problem 2"

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==Problem 2==
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==Problem==
  
 
Define the operation <math>\star</math> by <math>a \star b = (a+b)b.</math> What is <math>(3 \star 5) - (5 \star 3)?</math>
 
Define the operation <math>\star</math> by <math>a \star b = (a+b)b.</math> What is <math>(3 \star 5) - (5 \star 3)?</math>
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Substitute and simplify.
 
Substitute and simplify.
 
<cmath>(3+5)5 - (5+3)3 = (3+5)2 = (8)2 = \boxed{\textbf{(E) }16}</cmath>
 
<cmath>(3+5)5 - (5+3)3 = (3+5)2 = (8)2 = \boxed{\textbf{(E) }16}</cmath>
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==See Also==
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{{AMC10 box|year=2007|ab=B|num-b=1|num-a=2}}

Revision as of 16:38, 4 June 2011

Problem

Define the operation $\star$ by $a \star b = (a+b)b.$ What is $(3 \star 5) - (5 \star 3)?$

$\textbf{(A) } -16 \qquad\textbf{(B) } -8 \qquad\textbf{(C) } 0 \qquad\textbf{(D) } 8 \qquad\textbf{(E) } 16$

Solution

Substitute and simplify. \[(3+5)5 - (5+3)3 = (3+5)2 = (8)2 = \boxed{\textbf{(E) }16}\]

See Also

2007 AMC 10B (ProblemsAnswer KeyResources)
Preceded by
Problem 1
Followed by
Problem 2
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All AMC 10 Problems and Solutions