A rancher has a square cow pen with side length x. He decides to change the shape of the pen while still using the same amount of fencing materials. The equation

(x + 10)(x - 10) = 300 represents the relationship of the new side lengths (in feet)

of the pen and its area (in square feet).

a. If 300 represents the area of the new cow pen, what do the expressions

(x + 10) and (x - 10) each represent?

b. Find x, the original side length (in feet) of the square pen. Show your reasoning.

a) x+ 10 is the length of the ranch

x - 10 is the width of the ranch

b) 20 feet

Step-by-step explanation:

Area of the square ranch = L²

L is the side length of the ranch

If the equation

(x + 10)(x - 10) = 300 represents the relationship of the new side lengths (in feet)

Then we can find x where;

x + 10 is the new length of the ranch

x - 10 is the new width of the ranch

Open the parenthesis

equation

(x + 10)(x - 10) = 300

x²²-10x + 10x - 100 = 300

x² - 100 = 300

x² = 300+100

x² = 400

x = √400

x = 20

Hence the original length of the square pen is 20 feet

62.5 paisa

step-by-step explanation:

4000*70 = 280000

280000-(2000*90) = 100000

4000-2400 = 1600

100000/1600 = 62.5

( give brainliest)

d. millimeters per hour.

step-by-step explanation:

we are given that,

carlo used a rain gauge to measure the amount of water his lawn is receiving from the sprinklers.

since, according to the options, we see that,

water cannot be measured by 'miles per hour', 'meters per second' and 'grams per seconds'.

we get that, the water can be measured by 'millimeters per hour'.

hence, the appropriate rate for describing the amount of water is 'millimeters per hour'.