Solve the inequalites
2(x^2 - 2)>7x
show your working.... This isn't my Homework, I just made up this question and want to see who can answer it correctly..
2006-11-16 19:25:23 · 4 answers · asked by Miss LaStrange 5 in Science & Mathematics ➔ Mathematics
it is a piece of cake
firstly,expand the formula ,then you will find that
2X^2-4>7X
move 7x to right side,then it would be
2X^2-7X-4>0 X^2-3.5X-2>0
(X-1.75)^2-2-1.75^2>0
so (X-1.75)^2>2+1.75^2
(X-1.75)^2>5.0625
so X-1.75>2.25 or X-1.75<-2.25
so X>4 or X<-0.5
2006-11-16 19:43:34 · answer #1 · answered by peterwan1982 2 · 1⤊ 0⤋
Your inequality holds if x>4 or x<-1/2
2x^2-7x-4>0
(2x+1)(x-4)>0
to be greater than 0 both factors must positive or both negative
They are both positive if x>4 and both negative if x<-1/2
2006-11-17 03:44:51 · answer #2 · answered by Jimbo 5 · 1⤊ 0⤋
2x^2-7x-4>0
(2x+1)(x-4)>0
2x+1>0 and x-4>0
x>-.5 and x>4
2006-11-17 03:39:48 · answer #3 · answered by James L 1 · 1⤊ 1⤋
not homework my @$$
2006-11-17 03:30:44 · answer #4 · answered by BLEHH 3 · 0⤊ 3⤋