Solve the Inequality for x (x-5)(x+4)>=0

$(x - 5) (x + 4) \geq 0$

Step 1

If any individual factor on the left side of the equation is equal to $0$ , the entire expression will be equal to $0$ .

$x - 5 = 0$

$x + 4 = 0$

Step 2

Set $x - 5$ equal to $0$ and solve for $x$ .

Set $x - 5$ equal to $0$ .

$x - 5 = 0$

Add $5$ to both sides of the equation.

$x = 5$

Step 3

Set $x + 4$ equal to $0$ and solve for $x$ .

Set $x + 4$ equal to $0$ .

$x + 4 = 0$

Subtract $4$ from both sides of the equation.

$x = - 4$

Step 4

The final solution is all the values that make $(x - 5) (x + 4) \geq 0$ true.

$x = 5, - 4$

Step 5

Use each root to create test intervals.

$x < - 4$

$- 4 < x < 5$

$x > 5$

Step 6

Choose a test value from each interval and plug this value into the original inequality to determine which intervals satisfy the inequality.

Test a value on the interval $x < - 4$ to see if it makes the inequality true.

Choose a value on the interval $x < - 4$ and see if this value makes the original inequality true.

$x = - 6$

Replace $x$ with $- 6$ in the original inequality.

$((- 6) - 5) ((- 6) + 4) \geq 0$

The left side $22$ is greater than the right side $0$ , which means that the given statement is always true.

True

Test a value on the interval $- 4 < x < 5$ to see if it makes the inequality true.

Choose a value on the interval $- 4 < x < 5$ and see if this value makes the original inequality true.

$x = 0$

Replace $x$ with $0$ in the original inequality.

$((0) - 5) ((0) + 4) \geq 0$

The left side $- 20$ is less than the right side $0$ , which means that the given statement is false.

False

Test a value on the interval $x > 5$ to see if it makes the inequality true.

Choose a value on the interval $x > 5$ and see if this value makes the original inequality true.

$x = 8$

Replace $x$ with $8$ in the original inequality.

$((8) - 5) ((8) + 4) \geq 0$

The left side $36$ is greater than the right side $0$ , which means that the given statement is always true.

True

Compare the intervals to determine which ones satisfy the original inequality.

$x < - 4$ True

$- 4 < x < 5$ False

$x > 5$ True

$x < - 4$ True

$- 4 < x < 5$ False

$x > 5$ True

Step 7

The solution consists of all of the true intervals.

$x \leq - 4$ or $x \geq 5$

Step 8

The result can be shown in multiple forms.

Inequality Form:

$x \leq - 4 or x \geq 5$

Interval Notation:

$(- \infty, - 4] \cup [5, \infty)$

Step 9

Solve the Inequality for x (x-5)(x+4)>=0

Related Questions

Support LCMGCF.com by disabling your adblocker.