Please Help With Math Homework!? - XP Math - Forums
Sign Up FREE! | Sign In | Classroom Setup | Common Core Alignment

 XP Math - Forums Please Help With Math Homework!?
 User Name Remember Me? Password
 Register Arcade Members List Mark Forums Read

 Thread Tools Display Modes
 08-07-2007 #1 Erica D Guest   Posts: n/a Please Help With Math Homework!? I'm doing an algerbra review and I don't remember how you can tell if an equation has one solution, two solutions or no solution... Could anyone explain how?Some problems are...5x^2-9x+16=0x^2=2x-1and 3x^2-x-1=0
 08-07-2007 #2 SoulDawg4UGA Guest   Posts: n/a Use the quadratic formula, which is x = [-b +/- sqrt(b^2-4ac)]/2a. In the case of 5x^2-9x+16=0 a=5, b=(-9), and c=16, so we have [9 +/- sqrt(81-4(5)(16)]/2(5). Since 81-320 is a negative number, you cannot take the sqrt(-239), so in this case there is no solution.For the second equation above, you must put it into the form ax^2+bx+c=0, so convert it to x^2-2x+1=0. Then use the quadratic formula. We have [2+/- sqrt(4-4)]/2], which is 2/2 = 1. x=1 is the only solution because 2-sqrt(0) and 2+sqrt(0) is the same thing.For the third equation we have [1+/- sqrt(1-4(3)(-1)]/2(3), or [1-sqrt(13)]/6 and [1+sqrt(13)]/6 -- two solutions.Visit the following site: http://www.purplemath.com/modules/quadform.htmIt'll give you additional info on the quadratic formula.
 08-07-2007 #3 ou812 Guest   Posts: n/a graph it with your graphing calculator and see how many times it crosses the x axis

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Welcome     XP Math News     Off-Topic Discussion Mathematics     XP Math Games Worksheets     Homework Help     Problems Library     Math Challenges

All times are GMT -4. The time now is 12:44 PM.

 Contact Us - XP Math - Forums - Archive - Privacy Statement - Top

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
XP Math