Answer:
The students can group themselves in 360360 ways
Step-by-step explanation:
For this exercise we need to use the following equation:

This equation give us the number of assignation of n elements in k cell, where n1, n2, ..nk are the element that are in every cell
In this case we have 15 student that need to be assign in three vehicles with an specific capacity. This vehicles would be the equivalent to cells, so we can write the equation as:

Because the first vehicle have 7 seating, the second vehicle have 5 seating and the third vehicle have 3 seating.
Solving the equation we get 360360 ways to organized 15 students in three vehicles with capacity of 7, 5 and 3 seating.
X-y is positive when y is further away from 0, compared to x. In other words, when y is a larger negative
For example
x = -2
y = -5
x-y = -2-(-5) = -2+5 = 3
The sum of a number is the answer to an equation of a number plus a number you are correct.
Answer:
Tenacious tennis: y=5x+120
Totally Tennis: 8x
Toys r us: y=20x
Lego club: y=17x+36
Step-by-step explanation:
y=cost x= tennis court usage charge
Tenacious tennis: y=5x+120
Totally Tennis: 8x
8.)
y=cost x=lego set
Toys r us: y=20x
Lego club: y=17x+36
First make 20 into a fraction, then solve; 3/5 · 20/1. 60/5 = 12. Hope that helps!