có bao nhiêu cách cử 3 người trong một tổ gồm 12 người đi lao động ( biết ai cũng có khả năng lao động )

Answer these questions showing your work plz

Find the value of the variable and the length of each secant segment.

Eric has challenged himself to walk 24,000 steps in 4 days. if eric walks the same number of steps each day, which function represents the number of steps eric still needs to walk to reach his goal with respect to the number of days since he started his challenge? a. y = 8,000x − 24,000 b. y = -8,000x + 24,000 c. y = 6,000x − 24,000 d. y = -6,000x + 24,000