SOLUTION: multiply this polynoimials ? (3x + 4) (5x - 9)

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Question 198758: multiply this polynoimials
?

(3x + 4) (5x - 9)
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

%283x%2B4%29%285x-9%29 Start with the given expression.


Now let's FOIL the expression.


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


%28highlight%283x%29%2B4%29%28highlight%285x%29-9%29 Multiply the First terms:%283%2Ax%29%2A%285%2Ax%29=15%2Ax%5E2.


%28highlight%283x%29%2B4%29%285x%2Bhighlight%28-9%29%29 Multiply the Outer terms:%283%2Ax%29%2A%28-9%29=-27%2Ax.


%283x%2Bhighlight%284%29%29%28highlight%285x%29-9%29 Multiply the Inner terms:%284%29%2A%285%2Ax%29=20%2Ax.


%283x%2Bhighlight%284%29%29%285x%2Bhighlight%28-9%29%29 Multiply the Last terms:%284%29%2A%28-9%29=-36.


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So we have the terms: 15%2Ax%5E2, -27%2Ax, 20%2Ax, and -36


15%2Ax%5E2-27%2Ax%2B20%2Ax-36 Now add every term listed above to make a single expression.


15%2Ax%5E2-7%2Ax-36 Now combine like terms.


So %283x%2B4%29%285x-9%29 FOILs to 15%2Ax%5E2-7%2Ax-36.


In other words, %283x%2B4%29%285x-9%29=15%2Ax%5E2-7%2Ax-36.