Answer: The expression is undefined for x=4 and x=5.
The expression is undefined for any x that makes the denominator 0. This leads to solving a quadratic equation:
![\frac{x+3}{x^2-9x+20}\\x^2-9x+20\neq 0\\x_{1,2}\neq\frac{9\pm\sqrt{9^2-80}}{2}=\frac{9\pm1}{2}\\x_1\neq4\\x_2\neq5](https://tex.z-dn.net/?f=%5Cfrac%7Bx%2B3%7D%7Bx%5E2-9x%2B20%7D%5C%5Cx%5E2-9x%2B20%5Cneq%200%5C%5Cx_%7B1%2C2%7D%5Cneq%5Cfrac%7B9%5Cpm%5Csqrt%7B9%5E2-80%7D%7D%7B2%7D%3D%5Cfrac%7B9%5Cpm1%7D%7B2%7D%5C%5Cx_1%5Cneq4%5C%5Cx_2%5Cneq5)
The answer is 24.5 because
![19-13 \frac{1}{2} = 5 \frac{1}{2}](https://tex.z-dn.net/?f=19-13%20%5Cfrac%7B1%7D%7B2%7D%20%3D%205%20%5Cfrac%7B1%7D%7B2%7D)
so you add 5.5 from 19 to get the answer
The answer is C 3. she has a 50/50 chance of grabbing either black or white. Subtracting either a black or white sock, the probably of getting a matching pair is 1/3 from there.
Looks to Be answer A have a great day!