Answer:
[-3, ∞)
Step-by-step explanation:
There are many ways to find the range but I will use the method I find the easiest.
First, find the derivative of the function.
f(x) = x² - 10x + 22
f'(x) = 2x - 10
Once you find the derivative, set the derivative equal to 0.
2x - 10 = 0
Solve for x.
2x = 10
x = 5
Great, you have the x value but we need the y value. To find it, plug the x value of 5 back into the original equation.
f(x) = x² - 10x + 22
f(5) = 5² - 10(5) + 22
       = 25 - 50 +22
       = -3
Since the function is that of a parabola, the value of x is the vertex and the y values continue going up to ∞.
This means the range is : [-3, ∞)
Another easy way is just graphing the function and then looking at the range. (I attached a graph of the function below).
Hope this helped!
 
        
             
        
        
        
Answer:
b)-9,2
Step-by-step explanation:
x^2+7x-18=0
x^2+9x-2x-18=0
x(x+9)-2(x+9)=0
(x+9)(x-2)=0
therefore 
x=-9
x=2
 
        
             
        
        
        
Answer:
12870ways
Step-by-step explanation:
Combination has to do with selection
Total members in a tennis club = 15
number of men = 8
number of women = 7
Number of team consisting of women will be expressed as 15C7
15C7 = 15!/(15-7)!7!
15C7 = 15!/8!7!
15C7 = 15*14*13*12*11*10*9*8!/8!7!
15C7 = 15*14*13*12*11*10*9/7 * 6 * 5 * 4 * 3 * 2
15C7  = 15*14*13*12*11/56
15C7 = 6,435 ways
Number of team consisting of men will be expressed as 15C8
15C8 = 15!/8!7!
15C8 = 15*14*13*12*11*10*9*8!/8!7!
15C8 = 15*14*13*12*11*10*9/7 * 6 * 5 * 4 * 3 * 2
 15C8 = 6,435 ways
Adding both
Total ways = 6,435 ways + 6,435 ways
Total ways = 12870ways
Hence the required number of ways is 12870ways