11) adam can mop a warehouse in ten hours. wilbur can mop the same warehouse in nine
hours. if they worked together how long would it take them? be sure to respond in a complete
sentence that explains your answer in relation to the question.
12) working together, jessica and jill can install a new deck in 6 hours. had she done it
alone it would have taken jill 15 hours. how long would it take jessica to do it alone? be sure to
respond in a complete sentence that explains your answer in relation to the question.

Step-by-step explanation:

11) Adam's speed is 1 warehouse / 10 hours.

Wilbur's speed is 1 warehouse / 9 hours.

Their combined speed is:

1/10 + 1/9

9/90 + 10/90

19/90

Distance = rate × time

1 warehouse = 19/90 warehouse/hr × t

t = 90/19 hours

t ≈ 4.74 hours

Working together, they can mop the warehouse in 4.74 hours.

12) Jessica and Jill's combined speed is 1 deck / 6 hours.

Jill's speed is 1 deck / 15 hours.

Jessica's speed is:

1/6 − 1/15

5/30 − 2/30

3/30

1/10

Distance = rate × time

1 deck = 1/10 deck/hr × t

t = 10 hours

Working alone, it takes Jessica 10 hours to install a new deck.

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116