document.write( "Question 167067This question is from textbook College Algebra
\n" ); document.write( ": I don't understand how to get the final answer to this type of problem.\r
\n" ); document.write( "\n" ); document.write( "Fourth degree, zeros of -5,-2,1, and 3, and y-intercept of 15.\r
\n" ); document.write( "\n" ); document.write( "p(x)=a(x+5)(x+2)(x-1)(x-3)
\n" ); document.write( "p(0)=a(5)(2)(-1)(-3)=30a
\n" ); document.write( "30a=15 a=1/2\r
\n" ); document.write( "\n" ); document.write( "p(x)=1/2(x+5)(x+2)(x-1)(x-3) How do you mutiply out the four linear factors and the constant?\r
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Algebra.Com's Answer #123043 by Fombitz(32388)\"\" \"About 
You can put this solution on YOUR website!
Distributive property
\n" ); document.write( "Let's look at Z(C+D)=ZC+ZD.
\n" ); document.write( "What if Z=A+B?
\n" ); document.write( "Then
\n" ); document.write( "Z(C+D)=(A+B)(C+D)=ZC+ZD=(A+B)C+(A+B)D=AC+BC+AD+BD
\n" ); document.write( "So then,
\n" ); document.write( "\"%28x%2B5%29%28x%2B2%29=x%2Ax%2B5x%2B2x%2B10=x%5E2%2B7x%2B10\"
\n" ); document.write( "and
\n" ); document.write( "\"%28x-1%29%28x-3%29=x%2Ax%2B%28-3%29x%2B%28-1%29x%2B3=x%5E2-4x%2B3\"
\n" ); document.write( "This is the FOIL method for expanding quadratic equations from factors.
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\n" ); document.write( "Now the problem becomes,
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\n" ); document.write( "Let's look at the product of the two quadratics,
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\n" ); document.write( "We again have to use the distributive property and make sure we account for each term.
\n" ); document.write( "There are nine terms in all.
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\n" ); document.write( "\"%28x%5E2%2B7x%2B10%29%28x%5E2-4x%2B10%29=%0D%0Ax%5E4%2B3x%5E3-15x%5E2-19x%2B30\"
\n" ); document.write( "Now we'll put that back in our original function.
\n" ); document.write( "\"p%28x%29=%281%2F2%29%28x%5E4%2B3x%5E3-15x%5E2-19x%2B30%29\"
\n" ); document.write( "\"p%28x%29=%281%2F2%29x%5E4%2B%283%2F2%29x%5E3-%2815%2F2%29x%5E2-%2819%2F2%29x%2B15%29\"\r
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\n" ); document.write( "Check, as an exercise, that we didn't make any mistakes and that x= -5,-2,1, and 3 are in fact zeros of this polynomial.
\n" ); document.write( "\"p%280%29=15\"
\n" ); document.write( "So that checks out.
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