Christy buys a book for £17.40. A year later she sells the book for £9.57. Calculate the percentage decrease in the value of the book.
1 point
45%
35%
40%
55%
The price of a painting increases from £24000 to £27120. Work out the
percentage increase in the price of the painting *
1 point

Look at attachment. has all info needed. need

The manufacturer of a new product developed the following expression to predict the monthly profit, in thousands of dollars, from sales of the productwhen it is sold at a unit price of x dollars.-0.5x^2 + 22x - 224what is represented by the zero(s) of the expression? a. the profit when the unit price is equal to 0b. the unit price(s) when the profit is equal to 0c. the profit when the unit price is greatestd. the unit price(s) when profit is greatest

Hi i’m not sure how to do question 20 if u could explain how to do it that’d b great