Answer:
[tex]3x-1[/tex]
Step-by-step explanation:
The formula to find the area of a triangle:
[tex]A = \frac{bh}{2}[/tex]
Here, [tex]A[/tex] is the area, [tex]b[/tex] is the base and [tex]h[/tex] is the height.
However, we are looking for height, so let's rearrange the equation for [tex]h[/tex]:
[tex]A = \frac{bh}{2}\\2A = bh\\h = \frac{2A}{b}[/tex]
Now we know the formula to find the height, let's do so:
[tex]h = \frac{2(18x-6)}{12}\\\\h = \frac{36x-12}{12}\\\\h = 3x - 1[/tex]
Therefore, our final answer is [tex]3x-1[/tex].