document.write( "Question 175363: 2x^3 - 5x^2 + 22x + 51/2x + 3\r
\n" );
document.write( "\n" );
document.write( "answer: x^2 -4x +17\r
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( "need a break down of how my text book got that answer i know how they got x^2 and +17 not sure how they got the -4X\r
\n" );
document.write( "\n" );
document.write( "please break down answer in long division form radther then synthetic division \n" );
document.write( "
Algebra.Com's Answer #130421 by gonzo(654)![]() ![]() ![]() You can put this solution on YOUR website! here's how i did it and the answer i got. \n" ); document.write( "--- \n" ); document.write( "problem: \n" ); document.write( "(2x^3 - 5x^2 + 22x + 51) divided by (2x + 3) \n" ); document.write( "--- \n" ); document.write( "first part of quotient is x^2 because 2x * x^2 = 2x^3 \n" ); document.write( "x^2 * (2x+3) = (2x^3 + 3x^2) \n" ); document.write( "first remainder is (2x^3 - 5x^2 + 22x + 51) minus (2x^3 + 3x^2) = (-8x^2 + 22x + 51) \n" ); document.write( "--- \n" ); document.write( "second part of quotient is -4x because -4x * 2x = -8x^2 \n" ); document.write( "-4x * (2x+3) = (-8x^2 - 12x) \n" ); document.write( "second remainder is (-8x^2 + 22x + 51) minus (-8x^2 - 12x) = (34x + 51) \n" ); document.write( "--- \n" ); document.write( "third part of quotient is 17 because 17 * 2x = 34x \n" ); document.write( "17 * (2x+3) = (34x + 51) \n" ); document.write( "third remainder is (34x + 51) minus (34x + 51) = 0 \n" ); document.write( "--- \n" ); document.write( "the answer is: \n" ); document.write( "(x^2 - 4x + 17) \n" ); document.write( "--- \n" ); document.write( "to prove, multiply (2x+3) * (x^2-4x+17) and you should get back to the original equation. \n" ); document.write( "multiplying out, we get: \n" ); document.write( "2x^3 -8x^2 + 34x + 3x^2 - 12x + 51 \n" ); document.write( "combining like terms, we get: \n" ); document.write( "2x^3 -5x^2 + 22x + 51 \n" ); document.write( "this is the original equation so we're good. \n" ); document.write( "--- \n" ); document.write( "your question: \n" ); document.write( "how did they get the -4x? \n" ); document.write( "--- \n" ); document.write( "1. you always divide the highest order of the divisor into the highest order of the dividend. \n" ); document.write( "2. you then multiply the result of that division by the whole divisor. \n" ); document.write( "3. you then subtract the result of that multiplication from the dividend to get the remainder which becomes the new dividend \n" ); document.write( "4. you continue the first 3 steps until the highest order of the dividend is less than the highest order of the divisor. take that over the divisor and you have your final remainder. \n" ); document.write( "in this problem, your final remainder was 0 / (2x+3) which became 0 which meant you had no remainder. \n" ); document.write( "--- \n" ); document.write( "the highest order of the divisor was 2x \n" ); document.write( "--- \n" ); document.write( "the first time the dividend was the original equation so we divided 2x into the highest order of the dividend which was x^3 to get x^2 \n" ); document.write( "--- \n" ); document.write( "the second time the dividend was the first remainder so we divided 2x into the highest order of the dividend which was -8x^2 to get -4x. \n" ); document.write( "--- \n" ); document.write( "the third time the dividend was the second remainder so we divided 2x into the highest order of the dividend which was 34x to get 17. \n" ); document.write( "--- \n" ); document.write( "hope that helps. \n" ); document.write( "let me know if you're still unsure how they got the -4x. \n" ); document.write( "--- \n" ); document.write( " \n" ); document.write( " |