HELp i need a example

1/2 x + x + 2x = 28

Find all critical values for the function f(r)=2r/(6r^2+8) and then list them (separated by commas) in the box below. find the absolute maximum and absolute minimum values of the function f(x)=(x−2)(x−5)^3+10 . 0n each of the indicated intervals. enter 'none' for any absolute extrema that does not exist. interval = [1,4] what is the absolute min interval = [1,8]. what is the absolute min