The police department uses a formula to determine the speed at which a car was going when the driver applied the
brakes, by measuring the distance of the skid marks. The
equation d = 0.0015r^2 + r models the distance, d, in feet
traveled after applying the brakes in a car moving
r miles per hour (r is the speed of the car).
If the distance the car traveled after applying the brakes
equals 88 feet, what, what was the speed of the car? *
*Round your answer to the nearest hundredth miles per hour.

mph

9514 1404 393

  78.71 mph

Step-by-step explanation:

You're looking for the solution to ...

  d = 88

  0.0015r^2 +r = 88

  0.0015r^2 +r -88 = 0

Using the quadratic formula*, we find ...

  r = (-1 +√(1² -4(0.0015)(-88)))/(2×0.0015)

  r = (-1 +√1.528)/0.003 = 0.236123/0.003 = 78.7077

The speed of the car was about 78.71 mph.

_____

* The quadratic formula will also give a negative answer of about -745 mph, which is not relevant to the situation.

to find the unit price, we must figure out the cost of one item (in this case one dish towel).   to do this, we divide the total price ($7.92) by the number of items bought (for this problem it is 8, because there are eight dish towels in one pack).  

$7.92/8 = $0.99

therefore, the unit price, or the price of one dish towel, is $0.99.

hope this !

so a parallelogram is just like a square base times height. multiply 40 and 39 to get 1560 inches.

a triangle is base times height divided by two. so multiply 7.9 and 5 and then divide it by 2 to get 19.75inches.

the kite can be split into two separate triangles and added together to get the total area. 30 x 4 /2 which equals 60. make sure to double it for the two triangles making 120.