Three postal workers can sort a stack of Mail in 40 minutes, 30 minutes, and 120 minutes, respectively. Find how long it takes them to sort the mail if all three work together

Karianne and lucius are analyzing a linear function on a graph. karianne says that unit rate is equal to rate of change, but that slope is calculated differently. lucius says that unit rate, rate of change, and slope are calculated the same way. who is correct? explain your answer.

Which expression is equivalent to -5(3x - 6/7)

Rewrite the polynomial -9x5 + 36x4 + 189x3 in factored form.