Simplify (1-2z)(1+2z)i've already done the math and gotten - 4z^2+1 (which is correct when i check) but it's not in my list for the multiple choice question i'm on. the answers i have are the following: a) 1 - 4zb) 1 - 4z - 4z^2c) 4z^2 - 4z - 1d) 4z^2 - 1if someone could tell me which answer would be correct in this situation, that would be amazing. you to anyone who takes the time to figure this out!

An airplane consumes fuel at a constant rate while flying through clear skies, and it consumes fuel at a rate of 64 gallons per minute while flying through rain clouds. let c represent the number of minutes the plane can fly through clear skies and r represent the number of minutes the plane can fly through rain clouds without consuming all of its fuel. 56c+64r < 900056c+64r< 9000 according to the inequality, at what rate does the airplane consume fuel while flying through clear skies, and how much fuel does it have before takeoff? the airplane consumes fuel at a rate of gallons per minute while flying through clear skies, and it has gallons of fuel before takeoff. does the airplane have enough fuel to fly for 60 minutes through clear skies and 90 minutes through rain clouds?

This is about circle theorems. someone asap : (

The median am of triangle ∆abc is half the length of the side towards which it is drawn, bc . prove that triangle ∆abc is a right triangle, and find angle mac and abm