diana is earning money by mowing lawns. She charges $15 per yard. Lawn mover rentals costs $30. Write and solve an inequality to find the minimum number of yards she must mow to make a profit of at least $40.

Question

anonymous · Answer

@zepdrix

zepdrix · Answer

So we have some yards.... let's call that uhhh $\Large\rm \mathcal y$.
Diana charges 15 per yard, or 15 per $\Large\rm \mathcal y$.

$\Large\rm 15\mathcal y$
But she starts out in the negative, she spends 30 dollars of her own money to get started.
So here is the expression we're working with:
$\Large\rm 15\mathcal y-30$

15 dollars per yard, minus the 30 dollars she initially invested.

zepdrix · Answer

Mmm so I guess with the way I set this up....
She wants to know when she has made 70 dollars,
the 30 dollars that she initially invested, plus 40 profit.

zepdrix · Answer

$$\Large\rm 70=15\mathcal y-30$$

anonymous · Answer

ty ! <3

zepdrix · Answer

Mmm maybe I set that up wrong :c
hold on hold on.. gotta get my head on straight.

anonymous · Answer

ok <3

zepdrix · Answer

Yah I didn't need to put 70, that was silly.
$\Large\rm 15\mathcal y-30$  <- This is the amount of money she has made after mowing y yards.
So if she mows 2 yards, she earns 30 from mowing, and breaks even because of the rental cost. So her profit would be zero.

So this expression is showing profit already.

$$\Large\rm 40=15\mathcal y-30$$Ya ya ya ya ya.. that looks better I think.
Do you understand how to solve for Y?

anonymous · Answer

yeah thanks so much! <3

zepdrix · Answer

k :3