Brandon typically takes 2 less hours than Maria to assemble a bicycle if each works alone. Brandon and Maria worked together to assemble a bicycle for 3 hours, and then Maria finished the job without Brandon after an additional 1 hour. How long would it have taken Maria to assemble the bicycle alone? Do not include the units in your answer.
Call the part of the bike that Brandon can assemble in one hr = 1/ x
Call the part that Maria can assemble in one hour = 1 / ( x + 2)
Working together they assemble 1 /x + 1/(x +2) part of the bike
So
Part of the bike they can assemble in 3 hours + part Maria can assemble in one hour = 1
3 [1/x + 1 / (x + 2)] + (1)( 1/(x+ 2)) = 1
3/x + ( 4) / (x + 2) = 1
[ 3( x + 2) + 4x ] / [ x * (x + 2) ] = 1
7x + 6 = x^2 + 2x
x^2 - 5x - 6 = 0
( x - 6) (x + 1) = 0
Take the first factor and set = 0
x = 6
It takes Maria x + 2 = 8 hours to assemble the bike by herself