Answer:
m∠Y = 40º
Explanation:
The sum of the angles in a triangle is 180 degrees. In △WXY:
[tex]m\angle W+m\angle X+m\angle Y=180\degree[/tex]Substitute the given values:
[tex](10x+17)\degree+(2x-9)\degree+(3x+7)\degree=180\degree[/tex]First, solve for x:
[tex]\begin{gathered} 10x+2x+3x+17-9+7=180\degree \\ 15x+15=180\degree \\ 15x=180-15 \\ 15x=165 \\ x=\frac{165}{15} \\ x=11 \end{gathered}[/tex]Next, solve for the measure of angle Y:
[tex]\begin{gathered} m\angle Y=(3x+7)º \\ =3(11)+7 \\ =33+7 \\ m\angle Y=40\degree \end{gathered}[/tex]