Answer:
125° and 55°
Explanation:
∠ BCE and ∠ ECF are adjacent angles and are supplementary, thus
10x + 15 + 5x = 180, that is
15x + 15 = 180 ( subtract 15 from both sides )
15x = 165 ( divide both sides by 15 )
x = 11
Thus
∠ BCE = 10x + 15 = 10(11) + 15 = 110 + 15 = 125°
∠ ECF = 5x = 5(11) = 55°