SOLUTION: if y=2x+3 and x*y<0 then what is the range of x?

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Question 461906: if y=2x+3 and x*y<0 then what is the range of x?
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
If y = 2x + 3, then solve the inequality x(2x + 3) <0.
The critical numbers are 0, -1.5.
For x < -1.5, x(2x + 3) > 0.
For -1.5 < x < 0, x(2x + 3) < 0.
For x > 0, x(2x + 3) > 0.
Therefore the range of x is the interval(-1.5, 0).