document.write( "Question 175211: What is the remainder when 3t^2+5t-7 is divided by t-5? \n" ); document.write( "
Algebra.Com's Answer #130337 by gonzo(654)![]() ![]() ![]() You can put this solution on YOUR website! 3t^2 + 5t - 7 divided by t-5 \n" ); document.write( "--- \n" ); document.write( "t goes into 3t^2 by a factor of 3t. \n" ); document.write( "3t * (t-5) = 3t^2 - 15t \n" ); document.write( "--- \n" ); document.write( "3t^2 + 5t - 7 minus 3t^2 - 15t equals 20t - 7 \n" ); document.write( "--- \n" ); document.write( "t goes into 20t by a factor of 20 \n" ); document.write( "20 * (t-5) = 20t - 100 \n" ); document.write( "--- \n" ); document.write( "20t - 7 minus 20t - 100 equals 93 \n" ); document.write( "--- \n" ); document.write( "the remainder is 93/(t-5) \n" ); document.write( "--- \n" ); document.write( "the complete answer is 3t + 20 + 93/(t-5) \n" ); document.write( "--- \n" ); document.write( "to prove this is true, then (t-5) * (3t + 20 + 93/(t-5)) should equal 3t^2 + 5t - 7 \n" ); document.write( "--- \n" ); document.write( "when you multiply polynomials, each factor in one polynomial has to be multiplied by each factor in the other polynomial. \n" ); document.write( "this means that: \n" ); document.write( "(a + b) * (c + d + e) equals (ac + ad + ae) + (bc + bd + be) = first way \n" ); document.write( "alternatively, this also means that: \n" ); document.write( "(a + b) * (c + d + e) equals (ac + bc) + (ad + bd) + (ae + be) = second way \n" ); document.write( "--- \n" ); document.write( "the answer is the same either way. \n" ); document.write( "--- \n" ); document.write( "multiplying them out the first way, you get: \n" ); document.write( "(t-5) * (3t + 20 + 93/(t-5)) = t*(3t + 20 + 93/(t-5)) - 5*(3t + 20 + 93/(t-5)) \n" ); document.write( "which equals \n" ); document.write( "3t^2 + 20t + 93t/(t-5) - 15t - 100 - 5*93/(t-5) \n" ); document.write( "which equals \n" ); document.write( "3t^2 + 5t - 100 + 93t/(t-5) - 5*93/(t-5) \n" ); document.write( "which equals \n" ); document.write( "3t^2 + 5t - 100 + 93*(t-5)/(t-5) \n" ); document.write( "which equals \n" ); document.write( "3t^2 + 5t - 100 + 93 \n" ); document.write( "which equals \n" ); document.write( "3t^2 + 5t - 7 \n" ); document.write( "--- \n" ); document.write( "multiplying them out the second way, you get: \n" ); document.write( "(t-5) * (3t + 20 + 93/(t-5)) = (t-5) * 3t) + ((t-5) * 20) + (t-5)*93/(t-5) \n" ); document.write( "which equals \n" ); document.write( "3t^2 - 15t + 20t - 100 + 93 \n" ); document.write( "which equals \n" ); document.write( "3t^2 + 5t - 7 \n" ); document.write( "--- \n" ); document.write( "the answer is the same. \n" ); document.write( "the remainder is 93/(t-5) \n" ); document.write( "--- \n" ); document.write( " |