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: 30.72 miles per gallon
To find <span>best approximate for the average gas mileage at a speed of 60 miles per hour you need to replace the variable x with 60. The calculation would be:
</span><span> y=−0.0088x2+0.79x+15
y= -31.68 +47.4 + 15
y= 30.72
</span>
Answer:
Step-by-step explanation:
The given quadratic equation is
2x^2+3x-8 = 0
To find the roots of the equation. We will apply the general formula for quadratic equations
x = -b ± √b^2 - 4ac]/2a
from the equation,
a = 2
b = 3
c = -8
It becomes
x = [- 3 ± √3^2 - 4(2 × -8)]/2×2
x = - 3 ± √9 - 4(- 16)]/2×2
x = [- 3 ± √9 + 64]/2×2
x = [- 3 ± √73]/4
x = [- 3 ± 8.544]/4
x = (-3 + 8.544) /4 or x = (-3 - 8.544) / 4
x = 5.544/4 or - 11.544/4
x = 1.386 or x = - 2.886
The positive solution is 1.39 rounded up to the nearest hundredth
Answer: 6
Step-by-step explanation:
Given Data:
Number of people = 6
Amount of Gold to be shared = 40lbs
Subtract 2/3 from your answer.
Therefore
If six people are to share 40lbs of gold evenly
= 40lbs / 6
Divide through by 2
= 20lbs / 3
= 20lbs / 3 - 2/3
= 18/3
= 6
Each person would get approximately 6lbs of gold
Answer: The correct number of balls is (b) 4.
Step-by-step explanation: Given that a single winner is to be chosen in a random draw designed for 210 participants. Also, there is an equal probability of winning for each participant.
We are using 10 balls, numbered through 0 to 9. We are to find the number of balls which needs to be picked up, regardless of order, so that each of the 210 participants can be assigned a unique set of numbers.
Let 'r' represents the number of balls to be picked up.
Since we are choosing from 10 balls, so we must have

The value of 'r' can be any one of 0, 1, 2, . . , 10.
Now,
if r = 1, then

If r = 2, then

If r = 3, then

If r = 4, then

Therefore, we need to pick 4 balls so that each participant can be assigned a unique set of numbers.
Thus, (b) is the correct option.