Determine if each function is linear or nonlinear.
a= linear b=non-linear

3x+y=12 a or b
y= \frac{6}{y} -2 a or b
y= \frac{x}{2} -3 a or b
y=3 x^{3} +5 a or b
y=x a or b

Achemist has 200 ml of a 10% sucrose solution. she adds x ml of a 40% sucrose solution. the percent concentration, y, of the final mixture is given by the rational function: the chemist needs the concentration of the final mixture to be 30%. how many milliliters of the 40% solution should she add to the 10% solution to get this concentration?

Solve 13 + w/7= -18 (w/7 is a fraction)

Find y to the nearest hundreds place