Step-by-step explanation:
Sn=n/2(2a+(n-1)d)
910=n/2{2a+(n-1)d}
1820=n{2a+(n-1)d}
1820=20{2a+(20-1)d}
1820=20{2a+19d}
91=2a+19d
An=a+(n-1)d
95=a+(20-1)d
95=a+19d
91=2a+19d
---------------
4=-a
a=-4
91=2a+19d
91=2(-4)+19d
91=-8+19d
91+8=19d
99=19d
d=99/19
A=-4
Answer:
B.
the complementary angles form a right angle with the shared ray
The children's ticket would be $7 each and the adult ticket would be $9.
