SOLUTION: (x+4)(x-5) Please solve using multiplication

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Question 381552: (x+4)(x-5) Please solve using multiplication
Found 2 solutions by Fombitz, jim_thompson5910:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Use the FOIL method,
%28x%2B4%29%28x-5%29=x%5E2-5x%2B4x-20
%28x%2B4%29%28x-5%29=highlight%28x%5E2-x-20%29

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

%28x%2B4%29%28x-5%29 Start with the given expression.


Now let's FOIL the expression.


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


%28highlight%28x%29%2B4%29%28highlight%28x%29-5%29 Multiply the First terms:%28x%29%2A%28x%29=x%5E2.


%28highlight%28x%29%2B4%29%28x%2Bhighlight%28-5%29%29 Multiply the Outer terms:%28x%29%2A%28-5%29=-5%2Ax.


%28x%2Bhighlight%284%29%29%28highlight%28x%29-5%29 Multiply the Inner terms:%284%29%2A%28x%29=4%2Ax.


%28x%2Bhighlight%284%29%29%28x%2Bhighlight%28-5%29%29 Multiply the Last terms:%284%29%2A%28-5%29=-20.


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So we have the terms: x%5E2, -5%2Ax, 4%2Ax, -20


x%5E2-5%2Ax%2B4%2Ax-20 Now add every term listed above to make a single expression.


x%5E2-x-20 Now combine like terms.


So %28x%2B4%29%28x-5%29 FOILs to x%5E2-x-20.


In other words, %28x%2B4%29%28x-5%29=x%5E2-x-20.


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim