Question:

Find a1 and d for the arithmetic series. S12 = -108, a12 = -20 a1 = _____.

Find a1 and d for the arithmetic series.
S12 = -108, a12 = -20
a1 = _____.

Find a1 and d for the arithmetic series. S12 = -108, a12 = -20 a1 = _____.