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

We know the rule of change: a b/c= (ac+b):c
So we have 2 7/8= (2x8+7):8= 23/8
and the second: 2 1/4 = (2x4+1):4= 9/4
We do the division: 23/8: 9/4= 23/8 x 4/9= (23x4):(8x9)= 23/18= 1 5/18
Answer:
C. 700 km/hour
Step-by-step explanation: