Answer:
m∠Y = 40°
Explanation:
The sum of the three angles of a triangle must equal 180°
Thus
m∠W + m∠X + m∠y = 180°
→ (10x + 17) + (2x - 9) + (3x + 7) = 180
→ 10X + 17 + 2X + 9 + 3X + 7 = 180
Collecting like terms
→ 10X + 2X + 3X + 17 - 9 + 7 = 180°
→ 15x + 15 = 180
Subtract constant 15 from both ssides:
→ 15x + 15 - 15 = 180 - 15
→ 15x = 165
Divide both sides by 15
→ 15x/15 = 165/15
→ x = 11
m∠Y = 3x + 7
m∠Y = 3 x 11 + 7
m∠Y = 33 + 7
m∠Y = 40°