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:
7,15,19,34 are not multiples of four. to find this answer out just divide four into them.
Answer:
B) Experiment: you imposed a treatment (new fertilizer on some plants, old on others) to determine its effect.
Step-by-step explanation:
In this situation, the fertilizer developer wants to evaluate a hypothesis, not just observe, by subjecting plants to two different treatments (new and old fertilizer) in order to determine which treatment provides a more desirable effect (more plant growth).
This process configures an experiment.
The answer is alternative B)
