How to get this? (No. 1 solve for theta)

Idont get this question can someone me solve it? ** the distance light travels in one second (1 light second) is about 1.86 ×10^5 mi. saturn is about 475 light-seconds from the sun. about how many miles from the sun is saturn..my guess is 8.83* 10^7 you so much

If f(x) = 2x + 8 and g(x) = x4, what is (gº)?

Simplify the rational expression. state any restrictions on the variable. t^2-4t-12 / t-8 the / is a fraction sign.