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Popular >

x^2-9x-18>0

Solution

x^{2} - 9 x - 18 > 0

Solution

x < \frac{- 3 17 + 9}{2} or x > \frac{3 17 + 9}{2}

+2

Interval Notation

(- \infty, \frac{- 3 17 + 9}{2}) \cup (\frac{3 17 + 9}{2}, \infty)

Decimal Notation

x < - 1.68465 \dots or x > 10.68465 \dots

Solution steps

x^{2} - 9 x - 18 > 0

Complete the square

x^{2} - 9 x - 18 : (x - \frac{9}{2})^{2} - \frac{153}{4}

(x - \frac{9}{2})^{2} - \frac{153}{4} > 0

Move

\frac{153}{4}

to the right side

(x - \frac{9}{2})^{2} > \frac{153}{4}

For

u^{n} > a

, if

n

is even then

x - \frac{9}{2} < - \frac{153}{4} or x - \frac{9}{2} > \frac{153}{4}

x - \frac{9}{2} < - \frac{153}{4} : x < \frac{- 3 17 + 9}{2}

x - \frac{9}{2} > \frac{153}{4} : x > \frac{3 17 + 9}{2}

Combine the intervals

x < \frac{- 3 17 + 9}{2} or x > \frac{3 17 + 9}{2}

Popular Examples

2/3 (y+2)-5/6 (y-1)= 5/4 (y-3)-4

\frac{2}{3} (y + 2) - \frac{5}{6} (y - 1) = \frac{5}{4} (y - 3) - 4

factor 4-x^4 factor

4 - x^{4}

factor 3pix^3+42pix^2+147pix factor

3 π x^{3} + 42 π x^{2} + 147 π x

3 x^{3} + x^{2} \leq 14 x

factor x^3y^2-x^2y^3-xy^2+y^3 factor

x^{3} y^{2} - x^{2} y^{3} - x y^{2} + y^{3}

Frequently Asked Questions (FAQ)

What is x^2-9x-18>0 ?
The solution to x^2-9x-18>0 is x<(-3sqrt(17)+9)/2 \lor x>(3sqrt(17)+9)/2