SOLUTION: solve. approximate irrational roots to the nearest tenth. Together Anna and Carla can spray- paint a van in 8 hours. Alone it takes Anna 2 hours less than Carla. Find the time

Question 44160: solve. approximate irrational roots to the nearest tenth.
Together Anna and Carla can spray- paint a van in 8 hours. Alone it takes Anna 2 hours less than Carla. Find the time it takes each of them to paint the van alone. Give your answers to the nearest tenth of an hour. (units optional)
Answer by fractalier(6550) (Show Source): You can put this solution on YOUR website!
Let Carla's individual time be c. So Anna's time is c-2.
We set this one up like this
t/A + t/B = 1
8/c + 8/(c-2) = 1
now multiply by the LCD, c(c-2), and get
8(c-2) + 8c = c(c-2)
8c - 16 + 8c = c^2 - 2c
now collect like terms and solve...
c^2 - 18c + 16 = 0
This cannot be factored so let's try completing the square...
c^2 - 18c + 81 + 16 = 81
c^2 - 18c + 81 = 65
(c - 9)^2 = 65
c - 9 = � √65
c = 9 � √65
The negative root does not work since that would make Anna's time negative so Carla's time is
c = 9 + √65 or about 17.1 hours
Anna can do it in c-2 or about 15.1 hours
RELATED QUESTIONS
solve. approximate irrational roots to the nearest tenth. The difference of the square (answered by fractalier)

Al can paint a room in a hours working alone. Bill can paint a room in b hours working... (answered by stanbon)

Fred can paint a house in 10 hours. Together, Pat and Fred can paint the house in 8... (answered by jorel1380,ankor@dixie-net.com)

Fred can paint a house in 10 hours. Together, Pat and Fred can paint the house in 8... (answered by stanbon)

Working together, Carla and Elise can cut and split a cord of wood in 4 hours. Working... (answered by checkley77)

if anna can paint a house in 4 hours and joe can paint a house in 6 hours. how long will... (answered by nerdybill)

Hi there and thanks in advance. Betty and Karen working together can paint a house in... (answered by jorel1380)

Ms. Munford can paint a big truck in 8 hours. Mr. Fisher can paint a big truck in 10... (answered by josgarithmetic)

Andrew can paint a fence in 7 hours and Diana can paint the same fence in 4 hours. How... (answered by ptaylor,Alan3354)