Difference between revisions of "1950 AHSME Problems/Problem 16"

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== Problem==
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== Problem ==
  
 
The number of terms in the expansion of <math> [(a+3b)^{2}(a-3b)^{2}]^{2} </math> when simplified is:
 
The number of terms in the expansion of <math> [(a+3b)^{2}(a-3b)^{2}]^{2} </math> when simplified is:
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<math> \textbf{(A)}\ 4\qquad\textbf{(B)}\ 5\qquad\textbf{(C)}\ 6\qquad\textbf{(D)}\ 7\qquad\textbf{(E)}\ 8 </math>
 
<math> \textbf{(A)}\ 4\qquad\textbf{(B)}\ 5\qquad\textbf{(C)}\ 6\qquad\textbf{(D)}\ 7\qquad\textbf{(E)}\ 8 </math>
  
==Solution==
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== Solution ==
  
 
Use properties of exponents to move the squares outside the brackets use difference of squares.
 
Use properties of exponents to move the squares outside the brackets use difference of squares.
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<cmath>[(a+3b)(a-3b)]^4 = (a^2-9b^2)^4</cmath>
 
<cmath>[(a+3b)(a-3b)]^4 = (a^2-9b^2)^4</cmath>
  
Using the binomial theorem, we can see that the number of terms is <math>\boxed{\mathrm{(B)}\ 5.}</math>
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Using the binomial theorem, we can see that the number of terms is <math>\boxed{\mathrm{(B)}\ 5}</math>.
  
==See Also==
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== See Also ==
  
{{AHSME box|year=1950|num-b=15|num-a=17}}
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{{AHSME 50p box|year=1950|num-b=15|num-a=17}}
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[[Category:Introductory Algebra Problems]]
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{{MAA Notice}}

Latest revision as of 00:51, 12 October 2020

Problem

The number of terms in the expansion of $[(a+3b)^{2}(a-3b)^{2}]^{2}$ when simplified is:

$\textbf{(A)}\ 4\qquad\textbf{(B)}\ 5\qquad\textbf{(C)}\ 6\qquad\textbf{(D)}\ 7\qquad\textbf{(E)}\ 8$

Solution

Use properties of exponents to move the squares outside the brackets use difference of squares.

\[[(a+3b)(a-3b)]^4 = (a^2-9b^2)^4\]

Using the binomial theorem, we can see that the number of terms is $\boxed{\mathrm{(B)}\ 5}$.

See Also

1950 AHSC (ProblemsAnswer KeyResources)
Preceded by
Problem 15
Followed by
Problem 17
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All AHSME Problems and Solutions

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