Answer:
16
Step-by-step explanation:
Boys is written first so 3:4 the 3 stands for boy.
12 boys in class means that the 3 from 3:4 was multiplied 4 times so you do the same to other side. 4 times 4 is 16, therefore the answer is 16.
Answer:
Irrational numbers can look like fractions: 

Irrational numbers have never ending decimals. Pi and e are also irrational numbers.
Answer:
First of all the rate of change is -2, so the answer would be y = x - 2
Answer:
A= 40°
B= 35°
C= 15°
Step-by-step explanation:
Since it says if the triangles were accurately drawn, then A would be the same degree as Q. C would be the same degree as P. B would be the same degree as R. Since R's degree is missing I knew that a obtuse triangle was 90°. I added 40+15 and got 55. Then i subtracted 90-55 and got 35. So the unknown value would be 35°.
I hope this helps.