I need to know if i got these correct and if not which ones are wrong? thanks 1. Factor 9x^2-64 completely. (9x-8)(x+8) 2….

I need to know if i got these correct and if not which ones are wrong? thanks

1. Factor 9x^2-64 completely.
(9x-8)(x+8)

2. Factor x^2-18x-144
x(x-180)-144

3. Solve 3x(x-5)(3x+5)=0
(0,5,-5/3)

4. Factor x^2+12x+27 completely
(x+3)(x+9)

5. Solve (3x-7)(x+2)=0
(7/3,-2)

6.) Solve 2x(x+4)(4x-9)=0
(0,-4,9/4)

For problems 7-9 the length of the rectangle is 3 inches more than its width.

7. Write an equation for the area of the rectangle in terms of width, w.
A=w^2+3

8. If the area of the rectangle is 180 square inches, write an equation for the above situation.
180=w^2+3

9. Write an equation for the situation above by multiplying the factors together and setting the equation equal to zero.
w^2+3-180=0

10. What are the factors of the equation w^2+3w-180
(w+15)(w-12)

For the problems 11-13 a projectile is fired upward with an initial speed of 800 feet per second. It is given that h=-16t^2+800t (h is the height of the ball)

11. Factor the given equation completely
h=(-16t)(t-50)

12. What will you set h equal to in the equation to find how many seconds it takes for the projectile to hit the ground
h=0

13. Find how many seconds before the projectile hits the ground. Let Yv1=-16t^2+800t
50 seconds

For problems 14-16 the equation d=.05^2+r models the distance, d , in feet traveled by a car moving r miles per hour after the driver begins to stop the car.

14. Factor the equation d=.05^2+r
d=r(.05+1)

15. What is the domain of the situation above?
All positive integers

16. If the distance the car traveled after applying the brakes equals 20 feet, what does that mean to the officer investigating the accident? (HINT: let d=20, bring 20 to the right so that the equation equals zero, identify the coefficients A,B, and C and then use the quadratic formula to solve)

The car was going about 32.36 miles per hour

For problems 17-18 the height, h, of the ball t seconds after it is released for a jump shot in a basketball game can be modeled with the equation h=-16t^2+12t+8.

17. The rim of the basket is 10 feet high. What is the correct way to set up the problem to solve when the ball reaches this height?
10=-16t^2+12t+8

18. State the number of solutions to the problem and state if the ball has a chance of going into the basket.
There are 2 solutions, meaning 2 times when the ball is 10 ft high. the time that the ball reaches 10 feet on its way up and on its way down. One of these times will be the balls opportunity to pass through the hoop.

Posted in Uncategorized