Answer:
<h2>54m²</h2>
Step-by-step explanation:
<h3>METHOD 1:</h3>
You can use the Heron's formula:

where
<em>p</em><em> - half of perimeter</em>
<em>a, b, c</em><em> - lengths of sides</em>
We have

Calculate:

<h3>METHOD 2:</h3>
Let's check that it is not a right triangle.
If the sum of the squares of the two shorter sides is equal to the square of the longest side, then this triangle is rectangular.
We have

Check:

This is a right trianglr wherew 9m and 12m are legs and 15m is a hypotenuse.
The formula of an area of a right triangle is:

<em>a, b</em><em> - legs</em>
Substitute:

I think it’s A I hope it helps
What is there to solve
be more specific
C. Revising because it should be your last stage in the writing process before you publish
Combine like terms.
4x^3 -6x^3= -2x^3
-8x^2 +2x^2= -6x^2
Answer = -2x^3 -6x^2 +4