The usual price of a tv set was $500. turning the christmas holiday, the price of a tv set marked down to$413. what the percentage decrease in the price of a tv set?

With these 5 geometry questions! pls 1.)quadrilateral abcd is inscribed in this circle.what is the measure of ∠a ? enter your answer in the box.°2.)quadrilateral abcd is inscribed in a circle.what is the measure of angle a? enter your answer in the box.m∠a= 3.)quadrilateral abcd is inscribed in this circle.what is the measure of angle b? enter your answer in the box.m∠b= °4.)quadrilateral abcd is inscribed in this circle.what is the measure of angle a? enter your answer in the box.°5.) quadrilateral abcd is inscribed in this circle.what is the measure of angle c? enter your answer in the box.°

Pls the last one and it has to be like number 6

Subtract and simplify. (-y^2 – 4y - 8) – (-4y^2 – 6y + 3) show how you got the answer if your answer is right i will mark you