Three postal workers can sort a stack of mail 10 minutes , 35 minutes, and 70 minutes respectively. find how long it takes them to sort the mail if all three work together

9514 1404 393

  7 minutes

Step-by-step explanation:

The total of stacks per minute is ...

  1/10 +1/35 +1/70 = (7+2+1)/70 = 1/7 . . . . stacks per minute

The rate in minutes per stack is the reciprocal of this.

Working together, the workers can sort a stack of mail in 7 minutes.

you answer is a

step-by-step explanation:

-7

step-by-step explanation:

x^2 + 18x + 74 = (x + 9)^2 - 81 + 74

= (x + 9)^2 - 7.

so q = -7.