OA Lesson Quiz
Aaron can paint a door in 6 h, and Ana can do the same job in 3 h. Working together, how many hours will it take them to paint a door?
h

4.5

Step-by-step explanation:

that is

their rates =1/6, 1/3 respectively

total =1/2

if 1/2=9

1= 9/2

= 4.5

a4 - 3a2 - 1

step-by-step explanation:

step   1   :

equation at the end of step   1   :

  ((a4) -   3a2) -   1

step   2   :

trying to factor by splitting the middle term

2.1     factoring   a4-3a2-1  

the first term is,   a4   its coefficient is   1 .

the middle term is,   -3a2   its coefficient is   -3 .

the last term, "the constant", is   -1