SOLUTION: what is the factoring pattern for d^2-23d+60?

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Question 131578: what is the factoring pattern for d^2-23d+60?
Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
d^2-23d+60

List all the factor combinations of 60 by starting with 1:
1*60
2*30
3*20
4*15
5*12
6*10
7 doesn't work
8 doesn't work
9 doesn't work
10*6 is the same as 6*10, so now you have all the possibilities.
Notice that as the first number gets larger, the second number gets smaller.

Now, look for a combination of numbers that ADDS up to the middle term which is 23. This would be the 3*20 combination.

d^2-23d+60
(d-3)(d-20)

For additional help with factoring, especially trinomial factoring, please go to my website by clicking on my tutor name "rapaljer" anywhere in algebra.com. Take the first link on my homepage which is "Basic and Intermediate Algebra: One Step at a Time". Look for Chapter 2 in Basic Algebra, Section 2.04. See also my MATH IN LIVING COLOR pages.

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