SOLUTION: please multiply and simplify (3x+7)^2 thank you

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Question 187148: please multiply and simplify

(3x+7)^2

thank you
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

%283x%2B7%29%5E2 Start with the given expression.


%283x%2B7%29%283x%2B7%29 Expand. Remember something like A%5E2=A%2AA.


Now let's FOIL the expression.


Remember, when you FOIL an expression, you follow this procedure:


%28highlight%283x%29%2B7%29%28highlight%283x%29%2B7%29 Multiply the First terms:%283x%29%2A%283x%29=9x%5E2.


%28highlight%283x%29%2B7%29%283x%2Bhighlight%287%29%29 Multiply the Outer terms:%283x%29%2A%287%29=21x.


%283x%2Bhighlight%287%29%29%28highlight%283x%29%2B7%29 Multiply the Inner terms:%287%29%2A%283x%29=21x.


%283x%2Bhighlight%287%29%29%283x%2Bhighlight%287%29%29 Multiply the Last terms:%287%29%2A%287%29=49.


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So we have the terms: 9x%5E2, 21x, 21x, and 49


9x%5E2%2B21x%2B21x%2B49 Now add every term listed above to make a single expression.


9x%5E2%2B42x%2B49 Now combine like terms.


So %283x%2B7%29%5E2 FOILs to 9x%5E2%2B42x%2B49.


In other words, %283x%2B7%29%5E2=9x%5E2%2B42x%2B49.