Answer:
x = 6
Explanation:
The base of this triangle is x. The other two sides are equal and have length 3x - 4. The perimeter of the triangle is thus x + 2(3x - 4) = 34, which can be solved for x.
Multiplying as indicated, we get x + 6x - 8 = 34, or 7x = 42.
Dividing both sides by 7, we get x = 6.