Question

Fiona earns $10 for mowing each lawn and $5 per hour for her work. Write an inequality to show how many lawns she needs to mow in order to earn at least $135.

Answer 1

Answer: $\geq$ 9 lawns, assuming Fiona spends 1 hour per lawn.

Step-by-step explanation:

Let Y = the amount earned from mowing a lawn.  Let z be the number of hours worked on that lawn.

Y = $10 + $5(z)

We need to know the number of hours, z, for any particular lawn to be able to make this a valid equation.  Not having that, we really can't set up a valid equation.  

But let's assume z=1 for each and every lawn and see what we'd have.

Y = $10 + $5

Y = $15/lawn.

Fiona needs at least $135 for her Broadway ticket.

Let L be the number of lawns mowed.  We need:

L*($15/lawn) $\geq$ $135

L  $\geq$ 9 lawns