Catherine paid $185.30 for an mp3 player. if the price paid includes a 9% sales tax, which of the following equations can be used to determine the price of the mp3 player before tax? (let x represent the cost of the mp3 player and y represent the total cost after tax.)

y = $185.30

x = the orignal cost minus 9% or .09. To increase an objects value by 9% you need to multiply by 1 + .09 or 1.09. So, x being increases by 9% would equal y or $185.30

1.09x = y

1.09x = $185.30

Divide both sides by 1.09

x = $170

answer:   28.56 feet (approx)

step-by-step explanation:

since, triangle abc has measure of angle c equal to 55 degrees, measure of angle abc equal to 90 degrees, and length of bc equal to 20 feet.

we have to find out the measurement of segment ab.

therefore, tan 55° =

but bc = 20 feet.

⇒ tan 55 ° =  

⇒ ab = 20 × tan 55 °

⇒ ab = 20 × 1.42814800674

⇒ ab = 28.5629601348   ≈ 28.56 feet