In science class, the girl to boy ratio is 3 to 7.
if there are 50 students total in the class, how many are boys

There are 35 boys in the class.

Step-by-step explanation:

This question can be solved as a rule of three.

In science class, the girl to boy ratio is 3 to 7.

This means that for each 10 students, 7 of them are boys and 3 are girls.

So if for 10 students, 7 of them are boys, how many are boys for 50?

7 boys - 10 students

x boys - 50 students

There are 35 boys in the class.

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

30005

yes ok