Answer:
(First step for obtaining a common denominator for the two fraction)

Step-by-step explanation:

where,
a is acceleration of an object.(Need to calculate)





Now we will simplify above expression for a
First we make common denominator.
Common denominator is 7. So, we make both denominator 7. We multiply by 7 at top and bottom with 3. We get
(First step for obtaining a common denominator for the two fraction)
Now we combine the numerator


I'll try to understand this but I don't really get it because I'm in middle school
Answer:
19/20
Step-by-step explanation:
write all numerators above the common denominator 20
14+5/20
19/20

now, the first one, on the far-left.... can't see the height.. but I gather you do, now as far as its Base area, well, the bottom is just a 12x12 square, so the area of its base is just 12*12
now, the middle pyramid, has a height of 6, the base is also a square, 8x8, so the Base area is just 8*8
now the last one on the far-right
has a height of 8, the Base is a Hexagon, with sides of 6

The rows add up to

, respectively. (Notice they're all powers of 2)
The sum of the numbers in row

is

.
The last problem can be solved with the binomial theorem, but I'll assume you don't take that for granted. You can prove this claim by induction. When

,

so the base case holds. Assume the claim holds for

, so that

Use this to show that it holds for

.



Notice that






So you can write the expansion for

as

and since

, you have

and so the claim holds for

, thus proving the claim overall that

Setting

gives

which agrees with the result obtained for part (c).