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

(Created page with '==Problem 2== 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> <math>\textbf{(A) } -16 \qquad\textbf{…')
 
m (see also)
Line 1: Line 1:
==Problem 2==
+
==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>
Line 9: Line 9:
 
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>
 +
 +
==See Also==
 +
 +
{{AMC10 box|year=2007|ab=B|num-b=1|num-a=2}}

Revision as of 15:38, 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
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 10 Problems and Solutions