WILL MARK BRAINLIEST all the zeroes of the equation.
x^4–6x^2–7x–6=0
This in my answer plz tell me if im right.

Add the fractions and simplify 1/2+ 1/3

Aretha wanted to gather data about the cost of local bowling leagues in her area. she plotted the data and determined that the average bowling league costs consist of a one-time registration fee and a monthly fee modeled by the equation y = 15x + 20. identify and interpret the y-intercept in this model. the y-intercept is 20. this is the cost per month. the y-intercept is 20. this is the cost of registration. the y-intercept is 15. this is the cost of registration. the y-intercept is 15. this is the cost per month.

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.