8a+3b+8a-4b=
8a+8a+3b-4b=
16a-1b=
16a-b
Hope I didn't mess up for your sake!
There will be 23 layers of brick, because 7500/321 = 23 with 117 leftover.
Answer:
6
Step-by-step explanation:
Percentage by which the average value of mid sized car decreases each year = 8%
Retail value of a car today = v dollars
Amount of decrease in the value of the car after 1 year = (8/100) * v
= 2v/25 dollars
Then
The equation that represents the value of the car after 1 year = v - (2v/25) dollars
= (25v - 2v)/25 dollars
= 23v/25 dollars
So following this expression the value of the mid sized car can be easily determined after 1 year. I hope this is the answer you were looking for and the procedure is also clear to you.
Remember that c is the initial height. Since we the rocket is in a 99-foot cliff, c=99. Also, we know that the velocity of the rocket is 122 ft/s; therefore v=122
Lets replace the values into the the vertical motion formula to get:

Notice that the rocket hits the ground at the bottom of the cliff, which means that the final height is 99-foot bellow its original position; therefore, our final height will be h=-99
Lets replace this into our equation to get:


Now we can apply the quadratic formula

where a=-16, b=122, and c=198


or


or


or

Since the time can't be negative, we can conclude that the rocket hits the ground after 9 seconds.