A straight line passes through the points with coordinates (-1, -1), (3, 15) and (k, 23).
Work out the value of k.
You must show all your working.
Please help!

3. find the radius of circle p.4. find y.

If f(x)=2x+2and g(x)=x^3, what is (g•f)(2)

Abby is preparing fruit punch for her party. she starts with a bowl filled with liquid that has 1/2 fruit juice and 1/2 sprite, but she decides it's too fruity. so she pours out 1/4 of the liquid, and then fills the bowl up again with sprite. what fraction of the punch is now sprite?