Solve the Inequality X^2 - 2X - 8 < 0

First we need to solve the Inequality, looking at what two numbers add to give -2 and multiply to give -8 we find these to be -4 and +2. So we can now say that (X-4)(X+2)<0. Then I like to draw a quick diagram sketch to help visualise the problem so draw an x^2 sketch with roots at -2 and +4. Found by setting each bracket equal to 0. Then look at where this curve is less than 0 to give us an answer of -2<X<4. I would then recommend plugging in the numbers -3, 1 and 5 as a quick check.

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Answered by Liam C. Maths tutor

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