It is a quadratic number pattern
in Word Problem Answers by

Your answer

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
To avoid this verification in future, please log in or register.

1 Answer

First subtract the first term from each of the others to give us a series with three terms:

0, 3, 9.

We are told that this is a quadratic series, so let f(x)=ax²+bx where a and b are constants.

f(1)=0, f(2)=3, f(3)=9.

We get three equations:

f(1)=a+b=0, so b=-a; f(2)=4a+2b=3; f(3)=9a+3b=9. But 9a+3b=9 can be written 3a+b=3.

We only need two equations to find two unknowns, and so let’s see what happens if we substitute b=-a in f(2) and f(3):

4a-2a=3, so 2a=3 and a=3/2; 3a-a=3, so 2a=3 and a=3/2. These two equations are consistent so a=3/2 and b=-a=-3/2 is the solution. f(x)=3x²/2-3x/2.

The series is generated using the formula 3x²/2-3x/2+6, because we need to add back the first term and if we start with x=0 the formula gives us 6, x=1 gives us 6, x=2 gives us 9, x=3 gives us 15.


by Top Rated User (721k points)

Related questions

1 answer
asked Sep 25, 2015 in Algebra 1 Answers by anonymous | 94 views
1 answer
1 answer
asked Sep 24, 2013 in Other Math Topics by noe | 111 views
1 answer
asked Jan 11, 2014 in Other Math Topics by edrinique_cartwright | 147 views
1 answer
asked Oct 12, 2013 in Other Math Topics by Hannah | 139 views
1 answer
asked Jun 11, 2013 in Algebra 1 Answers by anonymous | 357 views
2 answers
2 answers
asked May 22, 2013 in Algebra 1 Answers by anonymous | 213 views
Welcome to, where students, teachers and math enthusiasts can ask and answer any math question. Get help and answers to any math problem including algebra, trigonometry, geometry, calculus, trigonometry, fractions, solving expression, simplifying expressions and more. Get answers to math questions. Help is always 100% free!
84,555 questions
89,526 answers
13,984 users