Wht the sum for this owo hello

Florence price's brownies and more sells all types of cookies and pastries. on tuesdays, they markdown all brownies 75% to a sale of $1.50 a dozen. find the selling price and the markdown of a dozen brownies.

65% of students in your school participate in at least one after school activity. if there are 980 students in you school, how many do not participate in an after school activity?

What is the result of adding the system of equations? 2x+y=4 3x-y=6