Answer:
in short, Yes they are always rational.
here's why...
E.g. suppose 
and 
are fractions, that means that a,b,c,d are all integers, and b and d are not zero. finding the sum the numerator, and denominator would also have to be integers. the denominator of the sum can't be zero since the denominators of the fractions were not zero, and would give 
and since they are bound by addition (sum means addition) they must also be rational since eit would equal a bigger integer than initially had
Step-by-step explanation:
Answer:
the population is everyone at the airport ,the sample is the 50 people that walked by Elizabeth
Answer:21
Step-by-step explanation: plug in 19 and 1
1x3 is 3 plus 19 is 21
1 cm = 20 km
so 3.5 cm would equal : 3.5 * 20 = 70 km <==
:1
i didnt understand the question because of my English sorry
:2
we all know that the total of degrees is 180 so 70+70=140
180-140=40
so the answer is 40
3:
we have a figure with 4 angle so the total of degrees is 360 so the answer is 126
4:
the answer most be 50 becuse we have a Special degree witch always equal 90 if we have recatngle so
x+40=90
X=50 the answer and if you want to try again choose the second one
2x-10=90
2x=100
X=50 same answe you see
5:
in this quastion i searched and find alot of answers any way
its should be 7 or 3 but the correct answer in my opinion its 7
its shows in the picture i sent hopefully its helpful to you i will try to translate the first quastion and sent it to you
