Please can someone help me

F(n + 1) = f(n) – 8. if f(1) = 100, what is f(6)?

Which number line represents the solution set for the inequality -1/2x> 24?

Look at the figure below: triangle abc is a right triangle with angle abc equal to 90 degrees. the length of ac is 5 units and the length of ab is 4 units. d is a point above c. triangle adc is a right triangle with angle dac equal to 90 degrees and dc parallel to ab. what is the length, in units, of segment cd?