Question

Sa se determine ratia unei progresii aritmetice stiind ca a10-a2=16.
Va rog mult ajutatima este urgent.

Answer 1

an=a1+(n-1)r
a10=a1+9r
a2=a1+r
a10-a2=9r-r=8r=16, r=2

Answer 2

$\it a_{10} =a_2+8r\ \ \ \ \ (1)$

$\it a_{10} -a_2 = 16\ \ \ \ (2)$

$\it (1), (2) \Longrightarrow a_2+8r-a_2=16 \Longrightarrow 8r=16 \Longrightarrow r =2$