Which of the following options have the same value 5% of 35

Write the expression as a constant , a single trigonometric function, or a power of a trigonometric function. sin x cos x/ tan x

Can someone factor this fully? my friend and i have two different answers and i would like to know if either of them is right. you in advance. a^2 - b^2 + 25 + 10a

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)