2010005501
Level:
B
The sum of the first and the second term of a geometric sequence is \( 2 \), the sum of the third and the fourth term is \( 18 \) and the common ratio is negative. Find the first term.
\( -1 \)
\( 1\)
\( 2 \)
\( \frac12 \)
\( -2 \)
