Answer:
x = 6.75
y = 11.25
Explanation:
Triangle BDC is a right triangle with BC is hypotenuse
=> y^2 = x^2 + 9^2
Triangle ABC is a right triangle with AC is hypotenuse
=> (12 + x)^2 = 15^2 + y^2
Substitute 2 equations then we have
(12 + x)^2 = 15^2 + (x^2 + 9^2)
x^2 + 24x + 144 = 225 + x^2 + 81
24x = 306 - 144
24x = 162
x = 162/24 = 6.75
y^2 = x^2 + 9^2
y^2 = 6.75^2 + 9^2
y^2 = 126.5625
y = √126.5625 = 11.25