Difference between revisions of "2006 AMC 12B Problems/Problem 2"
| (4 intermediate revisions by 3 users not shown) | |||
| Line 1: | Line 1: | ||
== Problem == | == Problem == | ||
| + | For real numbers <math>x</math> and <math>y</math>, define <math>x\spadesuit y = (x + y)(x - y)</math>. What is <math>3\spadesuit(4\spadesuit 5)</math>? | ||
| + | |||
| + | <math>\text {(A) } - 72 \qquad \text {(B) } - 27 \qquad \text {(C) } - 24 \qquad \text {(D) } 24 \qquad \text {(E) } 72</math> | ||
== Solution == | == Solution == | ||
| + | <math>4\spadesuit 5=-9</math> | ||
| + | |||
| + | <math>3\spadesuit -9=-72 \Rightarrow \text{(A)}</math> | ||
== See also == | == See also == | ||
| − | + | {{AMC12 box|year=2006|ab=B|num-b=1|num-a=3}} | |
| + | {{MAA Notice}} | ||
Latest revision as of 09:44, 4 July 2013
Problem
For real numbers 
and 
, define 
. What is 
?
Solution
See also
| 2006 AMC 12B (Problems • Answer Key • Resources) | |
| Preceded by Problem 1 |
Followed by Problem 3 |
| 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 12 Problems and Solutions | |
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. 
