Sixth grade
Because if you divide their total profit by the total amount of hours they worked, you would find that the sixth grade's income per hour is the highest.
Sixth grade: 170÷5=34
Seven grade: 112÷4=28
Eighth grade: 192÷6=32
X=⁻3 and x=1
because
a+b=2 which means a=3 and b=⁻1 which added up equals 2
a×b=⁻22 which means that 11 which is a×⁻2 which is b=⁻22
Hello :
the midepoint is( (-1+7)/2 ; (3+2)/2)
(3, 5/2) ... answer C