document.write( "Question 152515: How many real zeroes are there in f(x) = (x + 3)(x – 4)(x + 6)(x^2 + 7)?
\n" ); document.write( "@ This is fairly straightforward. Only the last factor results in imaginary solutions
\n" ); document.write( "a. 3
\n" ); document.write( "b. 5
\n" ); document.write( "c. 4
\n" ); document.write( "d. None of the above
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Algebra.Com's Answer #112185 by mducky2(62)\"\" \"About 
You can put this solution on YOUR website!

Let's find the zeroes of the function. Don't be fooled by the terminology. A zero of the function merely means any value of x that makes f(x) = 0. If any of the factors are zero, f(x) would equal zero. Therefore, we should individually solve for x with each factor equated to zero.
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\"x+%2B+3+=+0\"
\n" ); document.write( "\"x+=+-3\"
\n" ); document.write( "Since x is a real number, this looks like a real zero.
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\"x+-+4+=+0\"
\n" ); document.write( "\"x+=+4\"
\n" ); document.write( "Since x is a real number, this also looks like a real zero.
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\"x+%2B+6+=+0\"
\n" ); document.write( "\"x+=+-6\"
\n" ); document.write( "Since x is a real number, this still looks like a real zero.
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\"x%5E2+%2B+7+=+0\"
\n" ); document.write( "\"x%5E2+=+-7\"
\n" ); document.write( "\"x+=+sqrt%28-7%29\"
\n" ); document.write( "Any square root of a negative number will not be a real number, so this is not a real zero.
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It looks like there are 3 total zeroes. We know there can't be any more because we have equated every possible factor of the function with zero. Therefore, the answer is a.
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