Answer:
BC = 25
Explanation:
We can see that the angles on the bottom are equal, so it's safe to assume that it's an isosceles triangle. This means that both the longer sides are equal in length. In other words,
4x + 4 = 6x - 14
Now it's just a matter of solving the equation, starting with isolating x. We add 14 to both sides to do this.
6x = 4x + 18
Then, remove 4x from both sides to get:
2x = 18
x = 9
We're not finished, though. It's asking for the line BC's length. Plugging in x gives us the value.
2(9) + 7 = 25