At a store, notebooks are on sale for 78% off the regular price. The cost of a notebook is represented by n. Which of the following expressions does NOT represent the sale price of the notebooks?
O A n +0.22
OB. 0.22n
OC. n - 0.78n
OD. (1 -0.78)

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?

If m∠abc = 70°, what is m∠abd? justify your reasoning.  using the addition property of equality, 40 + 70 = 110, so m∠abd = 110°.  using the subtraction property of equality, 70 − 30 = 40, so m∠abd = 30°.  using the angle addition postulate, 40 + m∠abd = 70. so, m∠abd = 30° using the subtraction property of equality.  using the angle addition postulate, 40 + 70 = m∠abd. so, m∠abd = 110° using the addition property of equality.

Solve each quadratic equation by factoring and using the zero product property. x^2 + 18x = 9x