Answer: 30 in.
Step-by-step explanation:
If it's an equilateral triangle, all sides are the same length. Therefore
3x + 15 = 7x - 5
x = 5
After figuring out x = 5, replace the x with five and solve the equation.
3(5) + 15 = 30
7(5) - 5 = 30
Now that we know the length of two sides, we can state that the third side-length also equals 30 inches because it is an equilateral triangle, meaning all sides are congruent/ the same.
