Solve the inequality 2x1x2 2 The common solution of the firs
Solve the inequality (2x-1)(x+2)<0
Solution
We\'ll conclude that a product is negative if the factors are of opposite sign.
There are 2 caes of study:
1) (2x-1) < 0
and
(x+2) > 0
We\'ll solve the firts inequality. For this reason, we\'ll isolate 2x to the left side.
2x < 1
We\'ll divide by 2:
x < 1/2
We\'ll solve the 2nd inequality:
(x+2) > 0
We\'ll subtract 2 both sides:
x > -2
The common solution of the first system of inequalities is the interval (-2 , 1/2).
We\'ll solve the second systemof inequalities:
2) (2x-1) > 0
and
(x+2) < 0
2x-1 > 0
We\'ll add 1 both sides:
2x > 1
x > 1/2
(x+2) < 0
x < -2
Since we don\'t have a common interval to satisy both inequalities, we don\'t have a solution for the 2nd case.
So, the complete solution is the solution from the first system of inequalities, namely the interval (-2 , 1/2).
