Nonlinear inequalities in one variable
asked Jul 31 in Algebra 1 Answers by anonymous

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

2x²+13x<18, 2x²+13x-18<0, x²+13x/2-9<0, x²+13x/2+169/16-169/16-9<0, (x+13/4)²-313/16<0.

(x+13/4)²-(√313/4)²<0, (x+13/4+√313/4)(x+13/4-√313/4)<0.

The product of the two bracketed factors must be negative so one must be positive and the other negative to get this result. So x lies between -13/4-√313/4 and -13/4+√313/4, that is -13/4-√313/4<x<-13/4+√313/4.

√313=17.6918 so -7.673<x<1.173 approx as illustrated below:

 

 

answered Jul 31 by Rod Top Rated User (582,800 points)

Related questions

Welcome to MathHomeworkAnswers.org, 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!
81,658 questions
85,896 answers
2,190 comments
69,334 users