document.write( "Question 619304: (x² + x +8) (x-8) \n" ); document.write( "

Algebra.Com's Answer #389634 by Theo(13342) $\"\"$ $\"About$

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(x-8) * (x^2 + x + 8) is equal to:
\n" ); document.write( "x * (x^2 + x + 8) - 8(x^2 + x + 8) which is equal to:
\n" ); document.write( "x*x^2 + x*x + x*8 -8*x^2 - 8*x - 8*8 which is equal to:
\n" ); document.write( "x^3 + x^2 + 8x - 8x^2 - 8x - 64 which is equal to:
\n" ); document.write( "x^3 -7x^2 - 64
\n" ); document.write( "to prove this is true, do a reverse operation.
\n" ); document.write( "divide x^3 - 7x^2 - 64 by (x-8)
\n" ); document.write( "you can use synthetic division to make this easier.
\n" ); document.write( "you will get:
\n" ); document.write( "8 divided into 1 - 7 + 0 - 64 using synthetic division.
\n" ); document.write( "you will get an answer of:
\n" ); document.write( "1 + 1 + 8 + 0 which equates to:
\n" ); document.write( "x^2 + x + 8 with a remainder of 0
\n" ); document.write( "since that division by (x-8) got you back to your original expression of (x^2 + x + 8), you know that you did the multiplication right, and the result of the multiplication is:
\n" ); document.write( "x^3 - 7x^2 - 64
\n" ); document.write( "you use the distributive law of multiplication to get this answer.
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