Question

y' = sqrt(4y+21)

Answer 1

If you integrate that you will get
\[y= \frac{2}{\sqrt{4y+21}}+c\]

Answer 2

its a differential equation question, so you want all the y's on one side and only x's and C's on the other

Answer 3

Ooops:) your right....

Answer 4

i think i got it: use variable seperable

Answer 5

Congrats, hope it works out