How do you get the answer of 4n-9=-9

The radius r of a circle is increasing at a rate of 3 inches per minute. Find the rate of change of the area when r = 5 inches and r = 21 inches. (a) r = 5 inches

Zohar is using scissors to cut a rectangle with a length of 5x-2 and a width of 3x+1 out of a larger piece of paper. The perimeter of rectangle is 2 (5x-2) + 2 (3x+1) if x = 4 centimeters whst is total distance

What is the product? 13. - 6 - 11 1-14 g

What is 8.05 as a fraction and percent?

Explain how to find the quotient of 3.4 : 6

3x + 2y = 8 x + 2y = 4

A firework is fired vertically into the air at a speed of 100 m/s. The expression - 5t2 + 100t + 40 gives the height of the firework after t seconds. Factor this expression.

Six friends play golf. Their scores are 87,95, 92, 88, 91, and 96. What is the mean, median, and mode of the friends' scores?

X to the 2nd + 8x + 12 equals 0

4x^2-35x+49=0 solve by factoring