
Algebra PreAlgebra and Basic Algebra Math Forum 
 LinkBack  Thread Tools  Display Modes 
August 22nd, 2010, 02:45 PM  #1 
Newbie Joined: Aug 2010 Posts: 3 Thanks: 0  These equations are driving me to insanity!
Here is the first one: x2 ?5x =0 Looking at this equation, I assumed it was a quadratic because there is an = 0 sign at the end. But quadratics have the form 'xsquared + bx + c = 0'. I cannot find a solution to this question. Here is the other one: x +3 ? 1/x = 0 Same thing here  absolutely baffled. Somebody please help  I'm loading my shotgun as we speak! 
August 22nd, 2010, 02:53 PM  #2 
Global Moderator Joined: Oct 2008 From: London, Ontario, Canada  The Forest City Posts: 7,767 Thanks: 1017 Math Focus: Elementary mathematics and beyond  Re: These equations are driving me to insanity!
x^2  5x = 0, x(x  5) = 0, x = 5, x = 0. x + 3  1/x = 0, multiply both sides by x, x^2 + 3x 1 = 0, x = (3 ± ?(13))/2. 
August 22nd, 2010, 03:35 PM  #3 
Senior Member Joined: Jul 2010 From: St. Augustine, FL., U.S.A.'s oldest city Posts: 12,155 Thanks: 465 Math Focus: Calculus/ODEs  Re: These equations are driving me to insanity!
You were right, the first one is quadratic, c = 0. In the general form ax˛ + bx + c "b" and "c" can be zero, but "a" cannot. 
August 22nd, 2010, 05:42 PM  #4  
Newbie Joined: Aug 2010 Posts: 3 Thanks: 0  Re: These equations are driving me to insanity! Quote:
Bit new to the subject and was having trub getting my head round it. But to ask for your expertise once again. Can you please help with these ones. The first one is a simultaneous equation  (which i am still new to) and the second is asking me to express x in terms of y 2a  b = 8 3a + 2b = 5 And 'Write out a correct rearrangement of the formula to express x in terms of y' y =4(x +3) ?2x  
August 22nd, 2010, 05:52 PM  #5 
Global Moderator Joined: Oct 2008 From: London, Ontario, Canada  The Forest City Posts: 7,767 Thanks: 1017 Math Focus: Elementary mathematics and beyond  Re: These equations are driving me to insanity!
First one: [1] 2a  b = 8 [2] 3a + 2b = 5 Multiply [1] by 2: [3] 4a  2b = 16 Add [2] and [3]: 7a = 21, a = 21/7 = 3. From [1]: 2(3)  b = 8, b = 6  8, b = 2. Second one: y = 4(x +3)  2x y = 4x + 12  2x y = 2x + 12 y  12 = 2x (y  12)/2 = x. 

Tags 
driving, equations, insanity 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
I have this homework that is driving me crazy  DANDIS  Advanced Statistics  2  December 24th, 2011 01:12 PM 
factoring that is driving me insane  aaronmath  Algebra  3  November 8th, 2011 08:17 PM 
Please help. This has been driving me insane.  thfc1799  Advanced Statistics  1  November 21st, 2010 10:31 PM 
Please help this problem is driving me nuts!!!  sophieT66  Number Theory  4  October 7th, 2010 09:19 AM 
Number of possible outcomes when driving  groundwar  Algebra  6  October 27th, 2009 01:08 PM 