Test a value from each interval to see if it satisfies the original inequality.
Step 1
We will start by solving the related equation.
x^2-9x=- 20 ⇔ 1x^2+( - 9)x+ 20=0We see above that a= 1, b= - 9, and c= 20. Let's substitute these values into the Quadratic Formula to solve the equation.
Now we can calculate the first solution using the positive sign and the second solution using the negative sign.
x=9 ± 1/2
x=9 + 1/2
x=9 - 1/2
x= 10/2
x= 8/2
x=5
x=4
Step 2
The solutions of the related equation are 5 and 4. Let's plot them on a number line. Since the original is a strict inequality, the points will be open.
Step 3
Finally, we must test a value from each interval to see if it satisfies the original inequality. Let's choose a value from the first interval, x < 4. For simplicity, we will choose x=0.
