Difference between revisions of "2011 AMC 10A Problems/Problem 9"
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We have a rectangle of side lengths <math>a-(-b)=a+b</math> and <math>d-(-c)=c+d.</math> Thus the area of this rectangle is | We have a rectangle of side lengths <math>a-(-b)=a+b</math> and <math>d-(-c)=c+d.</math> Thus the area of this rectangle is | ||
| − | + | <cmath> | |
(a + b)(c + d) = ac + ad + bc + bd. | (a + b)(c + d) = ac + ad + bc + bd. | ||
| − | + | </cmath> | |
== See Also == | == See Also == | ||
{{AMC10 box|year=2011|ab=A|num-b=8|num-a=10}} | {{AMC10 box|year=2011|ab=A|num-b=8|num-a=10}} | ||
Revision as of 21:41, 6 February 2012
Problem 9
A rectangular region is bounded by the graphs of the equations 
and 
, where 
and 
are all positive numbers. Which of the following represents the area of this region?
Solution
We have a rectangle of side lengths 
and 
Thus the area of this rectangle is
![\[(a + b)(c + d) = ac + ad + bc + bd.\]](http://latex.artofproblemsolving.com/8/b/3/8b36d6c4d512d3fb5203fae215b0978980279b1d.png)
See Also
| 2011 AMC 10A (Problems • Answer Key • Resources) | ||
| Preceded by Problem 8 |
Followed by Problem 10 | |
| 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 | ||
