Answer:
[tex]x=8.5^o[/tex]
Step-by-step explanation:
Notice that since segments AB and DE are parallel, then angles [tex]\angle A[/tex] and [tex]\angle E[/tex] must be equal since they are alternate angles in between parallel lines.
So, [tex]\angle E = 50^o[/tex]. We also know that [tex]\angle C = 45^o[/tex], then the remaining angle ([tex]\angle D[/tex]) in triangle CDE must be such that added to the other two angles results in [tex]180^o[/tex]. That is:
[tex]\angle D = 180^o-\angle C-\angle E\\\angle D = 180^o-45^o-50^o\\\angle D= 85^o[/tex]
Now, since angle D equals 10 times x, we can solve for the unknown x in the equation:
[tex]\angle D=10\,x\\85^o=10\,x\\x=\frac{85^o}{10}\\\\x=8.5^o[/tex]
