x2-17x+42 =
W wjm11 Senior Member Joined Nov 13, 2004 Messages 1,417 Jan 30, 2012 #2 factoring x2-17x+42 = Click to expand... For nice explanations and examples, see this: http://www.purplemath.com/modules/factquad.htm
factoring x2-17x+42 = Click to expand... For nice explanations and examples, see this: http://www.purplemath.com/modules/factquad.htm
T takebackmath Guest Feb 9, 2012 #3 The X-factor- the easy way to factor trinomials x2-17x+42 remember it is ax2+bx+c Draw a large X Product X Sum 42 - The last number (c) X now what multiples to the top number and adds to bottom -17 - The middle number (b) List the products of 42: 1 times 42 -1 times -42 2 times 21 -2 times -21 3 times 14 -3 times -14 === This ones has a sum to -17 (The factors!) 42 -3 X -14 -17 So factors are (x-3)(x-14) This works on Trinomials where the number beside x2 is 1. Thanks Trevor Doyle, Math Teacher Mountain Oaks School Last edited by a moderator: Feb 9, 2012
The X-factor- the easy way to factor trinomials x2-17x+42 remember it is ax2+bx+c Draw a large X Product X Sum 42 - The last number (c) X now what multiples to the top number and adds to bottom -17 - The middle number (b) List the products of 42: 1 times 42 -1 times -42 2 times 21 -2 times -21 3 times 14 -3 times -14 === This ones has a sum to -17 (The factors!) 42 -3 X -14 -17 So factors are (x-3)(x-14) This works on Trinomials where the number beside x2 is 1. Thanks Trevor Doyle, Math Teacher Mountain Oaks School
