Select all that apply. Which representations show a direct variation?

y = -2/3 x

y = 2 x + 3

Input (x) 3 6 9 12 15
Output (y) 4 8 12 16 20

You have 6 dollars +12 pennies +to quarters + 4 dimes=2 nickels how much do you have

Table which ratio is equivalent to 3: 7? 6: 7 3: 21 24: 56 15: 30

Estimate the area under the curve f(x) = 16 - x^2 from x = 0 to x = 3 by using three inscribed (under the curve) rectangles. answer to the nearest integer.