Welcome :: Homework Help and Answers :: Mathskey.com
Welcome to Mathskey.com Question & Answers Community. Ask any math/science homework question and receive answers from other members of the community.

13,435 questions

17,804 answers

1,438 comments

774,954 users

solve the quadratic inequality. write the solution set in interval notation.

0 votes

x^2- 9x+ 18> 0

asked Apr 26, 2014 in ALGEBRA 2 by anonymous

1 Answer

0 votes

Quadratic inequality is x² - 9x + 18 > 0

Factor it like an equation

x² - 3x - 6x + 18 > 0

x(x - 3) - 6(x - 3) > 0

(x - 3)*(x - 6) > 0

Now product of two numbers can only be positive if both numbers are positive i.e >0 or both the numbers are negative ie. < 0

x - 3 > 0 and x - 6 > 0 => x > 6 ; or

x - 3 < 0 and x - 6 < 0 => x < 3

So answer has to be (- ∞, 3) U ( 6, ∞).

answered Apr 26, 2014 by joly Scholar

Related questions

...