Find the slope that passes through -3,1 and 7,5

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.

Atotal of 766 tickets were sold for the school play. they were either adult tickets or student tickets. there were 66 more student tickets sold than adult tickets. how many adult tickets were sold?

Solve the system of equations using the substitution method. {y=−3x+7x=−2y−16 enter your answers in the boxes.