Question

SUBPUNCTUL A SUPRR URGENT

Answer 1

$\displaystyle r=\frac{a_{m} -a_{n} }{m-n} =\frac{a_{8} -a_{1} }{8-1}=\frac{12 +2}{7}=2$

$\displaystyle a_{n} =a_{1}+ r\cdot (n-1)$

$\displaystyle a_{10} =a_{1}+ r\cdot (10-1)=-2+2\cdot9=16$