document.write( "Question 624035: Factor a trinomial whose leading coefficient is not 1? 6x^2-17x+12 \n" ); document.write( "
Algebra.Com's Answer #392528 by KMST(5328) You can put this solution on YOUR website! Here's the trick: \n" ); document.write( "Multiply the leading coefficient (6) times the independent term (12). \n" ); document.write( "(Do not worry much about the sign of the product for now). \n" ); document.write( "I got 72 as the product. How about you? \n" ); document.write( "Look for factor pairs that multiply to give you that product, and list them. \n" ); document.write( "I get: \n" ); document.write( "(1)(72)=72 \n" ); document.write( "(2)(36)=72 \n" ); document.write( "(3)(24)=72 \n" ); document.write( "(4)(18)=72 \n" ); document.write( "(6)(12)=72 \n" ); document.write( "(8)(9)=72 \n" ); document.write( "and no other pair of factors. \n" ); document.write( " \n" ); document.write( "OPTIONAL RATIONALE EXPLANATION: \n" ); document.write( "If the factoring was \n" ); document.write( "factors of that product, \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "BACK TO THE TRICK (even if you do not understand or do not care for the rationale): \n" ); document.write( "In the list of factor pairs above, look for factor pairs (consider all sign options now) that add up to the coefficient of the term in x (-17 in the case of the problem you posted) and multiply to give (6)(12)=72 (with its positive sign). \n" ); document.write( "At this point, you find: \n" ); document.write( "(-8)(-9)=72=(6)(12) \n" ); document.write( "and (-8)+(-9)=-17 \n" ); document.write( "Then, -17x could be the result of -8x plus -9x, and you could write the trinomial to be factored as \n" ); document.write( " \n" ); document.write( "The expression on the right helps you figure out the factorization. \n" ); document.write( "All you need now is some creative \"taking out common factors\" trick: \n" ); document.write( " |