Solution: ( x - y ) ( 2x - 3y) - 5x + 5y
First divide 35/2 with 2 to find the radius
r = 35/4
Circumference = 2.pie.r
= (2)(22/7)(35/4)
= 55
The answer is 55
(y = x + 6)
(y = 9x - 2)
(**since both of the equations equal y, set the equations equal to each other**)
(9x - 2 = x + 6)
(**now solve**)
(8x - 2 = 6)
(8x = 8)
(x = 1)
(**now plug x back into one of the equations to find y**)
(y = 1 + 6)
(y = 7)
(**Now we found the intersection, which is (1,7))
answer
115 problems
explanation
since each student works out the same number of problems, you want to divide (total problems)/(students) to get the problems per student
the 4 hours is irrelevant here
total problems / students
= 8970 / 78
= 115 problems
