Answer:

Step-by-step explanation:
The error in rounding a number is half of the unit of measure.
The number was rounded to the nearest 0.1 unit so the error is 1/2×0.1, which equals 0.05.
Now we add 3.7 and 0.05, which equals 3.75 and we also take 3.7 - 0.05, which equals 3.65
So, the error interval is:

Ok. so lets call the cost of each soda x. now, 3 packs of soda is 10 less than five packs of soda. so the price of 3 packs of soda is 3x, the price of five packs is 5x. now, it says that 3 packs is 10 less than five packs. that means that 3x=5x-10.
now, to find the price of a pack of soda, we have to isolate x.
add 10 to both sides to get 3x+10=5x. now, we subtact 3x on both sides to get 10=2x. divide by 2 on both sides, x=5. a pack of soda is 5 dollars
This really depends on the fraction; if there are variables in the equation, if they are full numbers,etc. I'd really recommend looking up khan academy on YouTube and that will really help you out!
Answer: 195.5 or 12 7/32
Step-by-step explanation:
There is no letter tetha in the table so I use α instead. However it is not sence to final result.
The expression is:
(sinα+cosα)/(cosα*(1-cosα))
Lets divide the nominator and denominator by cosα
(sinα/cosα+cosα/cosα)/(cosα*(1-cosα)/cosα)= (tanα+1)/(1-cosα)=
=(8/15+1)/(1-cosα)= 23/(15*(1-cosα)) (1)
As known cos²α=1-sin²α (divide by cos²α both sides of equation)
cos²a/cos²α=1/cos²α-sin²α/cos²α
1=1/cos²α-tg²α
1/cos²α=1+tg²α
cos²α=1/(1+tg²α)
cosα=sqrt(1/(1+tg²α))= +-sqrt(1/(1+64/225))=+-sqrt(225/(225+64))=
=+-sqrt(225/289)=+-15/17 (2)
Substitute in (1) cosα by (2):
1st use cosα=15/17
1) 23/(15*(1-cosα)) =23/(15*(1-15/17))= 23*17/2=195.5
2-nd use cosα=-15/17
2)23/(15*(1-cosα)) =23/(15*(1+15/17))= 23*17/32=12 7/32