Answer:
[tex]m\angle Y=40^\circ[/tex]
Step-by-step explanation:
Suppose we have a triangle WXY whose internal angles are:
[tex]m\angle W = 10x+17[/tex]
[tex]m\angle X=2x-9[/tex]
[tex]m\angle Y=3x+7[/tex]
The sum of the measures of the angles must be 180°, thus:
[tex]10x+17 + 2x-9+3x+7=180[/tex]
Simplifying:
15x + 15 = 180
Subtracting 15:
15x = 165
Dividing by 15:
x = 11
Thus, the measure of angle Y is
[tex]m\angle Y=3x+7=3*11+7=33+7=40[/tex]
[tex]\mathbf{m\angle Y=40^\circ}[/tex]
