SOLUTION: How do you solve these questions -3x< 9 x + 12< - 5x -x/4> -1 5x + 8 < 6x + 9

Algebra ->  Inequalities -> SOLUTION: How do you solve these questions -3x< 9 x + 12< - 5x -x/4> -1 5x + 8 < 6x + 9       Log On


   



Question 49147: How do you solve these questions
-3x< 9
x + 12< - 5x
-x/4> -1
5x + 8 < 6x + 9

Answer by tutorcecilia(2152) About Me  (Show Source):
You can put this solution on YOUR website!
These are solved the same way as you would solve regular equations, except when you multiply or divide by a negative number, switch the direction of the sign.
.
-3x< 9
-3x/-3>9/-3
x>-3
.
.
x + 12< - 5x
x + 12 -12< - 5x -12
x < - 5x -12
x +5x< - 5x + 5x -12
x + 5x< -12
6x< -12
6x/6< -12/6
x< -2
.
.
-x/4> -1
(4/1)(-x/4)> (4/1)(-1)
-x > -4
-x/-1 < -4/-1
x<4
.
.
5x + 8 < 6x + 9
5x -5x + 8 < 6x -5x + 9
8 < x + 9
8 - 9 < x + 9 - 9
-1 < x