answer
the number of buses is 3
the number of cars is 6
Step-by-step explanation:
total number of the students=165
total number of the vehicles=9
let x represent the number of cars
let y represent the number of buses
x+y=9...........equation 1
(the number of the cars plus the number of the buses= to the number of vehicles )
5x + 45y=165.......equation 2
(the number of student the car can hold plus the number of student the bus can hold= to the total number of the student in a class)
x+y=9.......eqn 1
5x +45y=165....eqn 2
make x the subject of the formula in eqn 1
x+y=9
x= 9-y
substitute for x= 9-y in eqn 2
5(9-y)+45y=165
45-5y+45y=165
-5y+45y=165-45
40y=120
divide both sides by 40
40y÷40=120÷40
y=3
since y represent number of buses,the numbet of bus is 3
Also,substitute for y=3 in eqn 1
eqn 1 is x+y=9
x+3=9
x=9-3
x=6
therefore,the number of cars is 6.
the constant rate of change, or average rate of change, is just its slope, so we can just pick any two points to get it.

The answer to that is a isosceles triangle <span />
Answer: The slope is 
Step-by-step explanation:
1. You need to apply the following formula for calculate the slope:

2. Given the points, (3,-4) and (7,6), you have:

3. Substitute these values into the formula for calculate the slope, as following:

4. Simplify the result. Therefore, you obtain that the slope is:

Hi.
I'm not 100% familiar with rational and irrational numbers, but I did a quick search.
I think the answer A.
Cheers~