Question

The length of a line segment ST is 17 units.

S is at (-4,9) and T is at (4, y).
Find the positive value of y.

Answer 1

y = 24

Explanation:

Pythagorean theorem

17² = (-4 - 4)² + (9 - y)²

17² = (-8)² + (81 - 18y + y²)

289 = 64 + 81 - 18y + y²

0 = y² - 18y - 144

0 = (y - 24)(y + 6)

y = 24

or

y = - 6