Determine the vertex of:
y = -3x2-6X+9

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?

Is ofat (-25, 0), (25, 0) co- (0, -15), (0, 15)?

The table below shows the angle measurements for triangle abc and triangle xyz. if triangle abc is similar to triangle xyz, what does angle z equal, in degrees?