Answer:
x=9,-1 and 
Explanation:
we have been given with the quadratic equation 
we compare the given quadratic equation with general quadratic equation
general quadratic is 
from given quadratic equation a=1,b= -8,c= -9
substituting these values in the formula for discriminant 

Now, to find the value of x
Formula is 
Now, substituting the values we will get

And rewritting the given equation by shifting 9 to right hand side of the given equation and taking minus inside the bracket so as to convert it in the form of

Answer: option d.
Step-by-step explanation:
We have the function:
y = f(x) = x^2 - 1
The output is 99 when y = 99, and the input is x.
Then we need to solve:
y = 99 = x^2 - 1
for x.
99 = x^2 - 1
99 + 1 =x^2
100 = x^2
√100 = x
10 = x
The correct option is d, input equals 10.
Step-by-step explanation:
The bacteria is always doubled because in the sequence we multiply the number by 2
3 x 2 = 6 x 2 = 12 x 2 = 24 x 2 = 48 x 2 = 96