Answer:
The length of EF = x = 18 cm
Option A is correct.
Step-by-step explanation:
Ware given perimeter of triangle = 97 cm
We need to find length of EF = x = ?
The length of EG = x+7
The length of EF = x
The length of GF = 3x
The formula used is: 
Putting values and finding x i.e length of EF

So, value of x=18 cm
The length of EF = x = 18 cm
Option A is correct.
Answer:
Sports players: For people that need high respiratory performance, rises in the pressure may difficult the things, so they would be affected by high pressure because this makes breathing a little bit harder.
Workers in construction and such: People that work a lot with their muscles, in heat environments (road workers, construction workers) may be affected by the same problem as before, and this makes the workers to exhaust in a shorter time than if they worked in a lower pressure environment.
Scientist: A lot of time, some experiments or investigations need a specific pressure to work, so changes in weather pressure may affect investigations, and because the changes are actually uncontrollable, the scientist are really affected by them.
Cups of flour=15 3/4=15+ 3/4=(4*15+3)/4=63/4
Cups of sugar=10 1/2=(2*10+1)/2=21/2
We solve this problem by rule of 3:
63/4 cups of flour--------------100 people
x------------------------------------ 25 people
x=(63/4 cups of flout * 25 people)/100 people=1575/400 cups of flour=
=63/16=(3*16+15)/16=3 15/16 cups of flour.
21/2 cups of sugar-----------------100 people
x-----------------------------------------25 people
x=(21/2 cups fo sugar * 25 people) / 100 people=525/200 cups of sugar= 21/8 =(2*8+ 5)/8=2 5/8 cups of sugar.
Answer: 3 15/16 cups of flour and 2 5/8 cups of sugar.
D 28/4=7 that is the answer for the question
Answer:
1- 
2- 1
3- -2
Step-by-step explanation:
1-
Add the numbers : 
Reduce the fraction with 5 : 
Solution : 
2-
Calculate the difference: 
Divide: 1
Solution: 1
3-
Subtract the numbers: 
Reduce the fraction : -2
Solution: -2