y = - 3
Since y varies directly as x then
y = kx ← ( k is the constant of variation )
to find k use y = - 1 when x = 3
k =
=
= - 
hence y = -
x
when x = 9, then
y = -
× 9 = - 3
42.052
place value and digits:
4 = tens
2 = ones
0 = tenths
5 = hundredths
2 = thousandths
5 is in the hundredths place. To find if you round up or down, look at the digit to the right (thousandths in this case). It is a 2, which is less than 5, so you round down.
42.052 rounded to the nearest hundredth is 42.05
hope this helps
The independent variables are the cost for one ticket and the number of student tickets. The cost of the tickets depends on the number of student tickets being purchased. The equation would be c = 7s.