A boy throws a rock off a cliff. The function shown below models the flight of the rock, where x equals the distance the rock is from the cliff in yards. What is the highest point the rock achieves?
f(x)= -x^2+4x+12

You move the constant to the right side and change its sign to be 9z= -6 -8. that’s the first step.the second step would be calculate the difference of -8-6 to get -14. you equation should now be 9z=-14the last step is to divide both sides by 9 to get z=-14/9hope this