Ihave this problem that i cant solve i need your . there's 4 multiple choice answers at the bottom, its one of those.
4/7 of the students in a classroom are girls. if there are nine boys in the class, how many total students are there?

a.14

b.28

c.21

d.12

To solve this problem, first we need to figure out what fraction of the class are boys.  

If we know that 4/7 of the students are girls, there are only 3/7 students left in the class, therefore they must be boys.

We know that there are 9 boys in the class.  (Let the variable x represent how many students total there are in the class.)

3/7x=9

If we divide both sides by 3/7, we get 

x=21.

Therefore, there are 21 students in the class.  Your answer is C. 21.

4/7 are girls
9 are boys
total=boys+girls=4/7+boys
boys=9
total=7/7
7/7=4/7+boys
subtract 4/7 from both sides
3/7=boys
therefor
3/7 of class=9
multily oth sides by 7/3 to clear fraction
class=63/3=21
class=21
answe ris C 21

Hello! mark me brainliest
answer:
congruent segments
step-by-step explanation:
congruent segments. take a line, cut it in half, superipose one half over the other half; you'll have congruence.