16a. 21cm. bc when it has 10 grams it moves half of that to 5cm so divide 42 by 2 and you get 21cm
17. remember y=mx+b; m is slope and b is y-intercept
you have to put your equation from point slope to y=mx+b
4x+y=6
subtract 4x from each side
y=-4x+6
slope = -4
y-intercept= 6
hope this helped :)
