Question

1. Find the variation constant and and an equation of variation where y varies directly as x and y y=42 when x=6
variation constant is K=
equation of variation is y=

2.Jack usually mows his lawn in 6 hours. Marilyn can mow the same yard in 4 hours. How muschtime would it take for them to mow the lawn together

Answer 1

since y = kx, k= 42/6 = 7
------------------------
1/t = 1/6 + 1/4 = 5/12
so,
t = 12/5

makes sense, since if they each took 6 hours, they could do it together in 3. If the each took 4 hours, they could do it together in 2.