First of all, observe that all fractions exist as long as b is not zero.
Multiply both numerator and denominator of the first fraction by 3:

Now all fractions have the same denominator. Under the assumption that b is not zero, multiply both sides by 3b:

Subtract 3b from both sides:

Subtract 2 from both sides:

Divide both sides by 2:

Thirty students are randomly sampled about their hair color.
This is for two reasons,. Firstly, randomness is very important in drawing conclusions. Secondly, it is less of an opinion question and more fact based.
The answer to number 5. Is option B
Answer:
x = 5.4
Step-by-step explanation:
(This question has already been answered, but both of the incorrect ones were deleted, so for future reference...)
Fig A is a scale image of Fig D. These two quadrilaterals are similar, and thus, the side lengths of corresponding sides are proportional. Set the proportion x/3 = 7.2/4 (you could alternatively write it as x/7.2 = 3/4 but for the simplicity's sake, and assuming anyone who has this problem would already know how to solve proportions like these...)
7.2/4 = 1.8
so
x/3 = 1.8
now multiply both sides by 3 to get x = 5.4
Answer: 252
Step-by-step explanation: