Answer:
D- The set of whole numbers were 1<_x<18
Step-by-step explanation:
x = 19
Vertical angles are equal
So
7x - 8 = 6x + 11
7x - 6x = 11 + 8
Answer:10
2+4+6+.....+20- (1+3+5+7+...+19)=(2-1)+(4-3)+(6-5)+....+(20-19)=1+1+...+1 ( de 10 ori= 10 times)
=10