Answer:
3x = 18
Step-by-step explanation:
Use the Pythagorean Theorem here:
30² = (3x)² + (4x)², or:
30² = 9x² + 16x² = 25x²
Taking the square root of both sides, we get √(30)² = √(25x²), or:
30 = ± 5x
Neglect -5x, since we are measuring distances, and distances are positive.
Then 5x = 30, and so x = 6
Thus, 3x = 3(6) = 18
