Explain why it might be useful to approximate the value rather than use the exact value

What percent of the circle below is shaded?

The function below is written in vertex form or intercept form. rewrite them in standard form and show your work. y = (x+4)(x+3)

You are choosing between two health clubs. club a offers membership for a fee of $ 28 plus a monthly fee of $ 20. club b offers membership for a fee of $ 20 plus a monthly fee of $ 22. after how many months will the total cost of each health club be the same? what will be the total cost for each club? in __ months the total cost of each health club will be the same.