You spend $30.40 on 4 cds. each cd costs the same amount and is on sale for 80% of the original price. a. write and solve an equation to find how much you spend on each cd. let p represent the price you pay for each cd.

Let "p" be the price you pay for each CD's

Since 4 CDs cost 30.40, the price you pay for each CD (p) is calculated as = total price for all CDs/ number of CDs

So, the price you pay for each CD (p) = 30.40/4 = $7.60

Since you paid 80% of the original price of each CD = 7.60/0.8 = $9.50

The price you paid for each CD = $7.60 per CD

The original price for each CD = $9.50

something that characterises a right triangle is the fact that we may use pythagoras' theorem to find any one of its sides given that we have the length of the other two sides. here, we have the length of the hypotenuse, √(87) yd, and one other side, √(23) yd, thus we can easily find the length of the remaining side using pythagoras' theorem as defined below:

c^2 = a^2 + b^2, where c is the length of the hypotenuse, and a and b are the lengths of the other two sides.

thus, given that c = √(87) and a = √(23), we may substitute these into the formula we defined above to get:

c^2 = a^2 + b^2

(√87)^2 = (√23)^2 + b^2 (substitute c = √87 and a = √23 into the equation)

87 = 23 + b^2 (evaluate (√87)^2 = 87 and (√23)^2 = 23 - remember that the square root of a number, squared will equal that very same number)

64 = b^2 (subtract 23 from both sides)

√64 = b (take the square root of both sides)

8 = b (evaluate √64 = 8)

therefor, the length of the unknown leg in the right triangle is 8 yd (first answer).