Please help, I really need this question answered :(

25$ + 10$ x 4 = 65$.

She needs to mow at least 4 lawns, the answer is B.

6.3

To solve this, we are going to use the Pythagorean inequality, which states that for an obtuse triangle or shorter sides and and longest side ,  .

We know from our problem that the shorter sides of our triangle are x cm and 3x cm, so and ; we also know that its longest side is 20 cm, so . Let's replace the values in our Pythagorean inequality an solve for :

And rounded to the nearest tenth:

The greatest possible value of x is 6.3 cm