7d = 56 minus the x in the middle
Here's the solution,
The given triangle is an <u>equilateral triangle</u>, because it's all angles measure 60° each
now,
Area of an equilateral triangle :
=》

where,
=》

=》

=》

or
=》

For this problem, I believe you would just have to plug in for x.
For example, -17 divided by 10 and so on.
The answer should be C, -70. -70 divided by 10 equals -7.
As an improper fraction, it is

.
A is correct. Hope my answer helped u :)