Answer: x = 3
Explanation:
Note that this triangle has 3 congruent angles. Therefore, it is an equilateral triangle. So, the sides will also be congruent.
So it can be said that : 6x - 3 = 3x + 6
+3
6x = 3x +9
-3x
3x = 9
/3
x = 3
By replacing x with 3, we can prove that these expressions all equal 15.
6(3) -3 = 18 - 3 = 15 . 3(3) + 6 = 9 + 6 = 15 . 5(3) = 15