5x = 4y - 3
Standard form is Ax + By = C, so first subtract 4y to both sides:
5x - 4y = -3
So you need to find the volume of the rectangular prism and the equation for that is V=l×w×h. If you plug those numbers in you'd get 9×12×23=2,484. If you multiply 2,484 by

because you'd have to pour out

of the water out so that it's only

of the volume of water is left. 2,484×

= 828mm.
Answer:
28 students
Step-by-step explanation:
Work backwards.
First, subtract 3:
115 - 3 = 112
Then, divide by 4:
112 ÷ 4 = 28
So, there are 28 math students in his class.