Question

a10=-2 e r= 2÷3.Calcule a1

Answer 1

$an= a1 + a(n-1).R \\\\ A10= a1 + (10-1).\frac{2}{3} \\\\ -2 = a1 + 9.\frac{2}{3} \\\\ -a1= +2+6 \\\\ -a1 = 8 \\\\ a1= 8$