Answer:
second one: -4x +6
third one: 4x - 16
fourth: 245x + 30
fifth: 81x - 21x
(last one) sixth: 1600x + 8x
( if this goes wrong then I did something else)
Let the capacity of bus be x students
And van be y students, now ;
From the given statements we get two equations ~
multiply the equation (2) with 2 [ it won't change the values ]
Now, deduct equation (1) from equation (3)
Therefore each bus can carry (x) = 45 students
Now, plug the value of x in equation (1) to find y ~
Hence, each van can carry (y) = 17 students in total.
The formula for the circumference is 2πr.
The diameter d is given, which is 2 times the radius r (d = 2r)
So you have to calculate π d = 3.142×1.8 ≈ 5.7