Question

In an a.p first term is -24 and 31st term is -34 . Find the 70th term

Answer 1

$\bf \huge\underline{ \underline{ANSWER}}$

Given ,

$\rm 1^{st} \ term = -24\\\\31^{st} \ term = -34$

____________________________________

$\ \ \ \ \ \\ \rm \bf\boxed {\bf Common \ difference = \dfrac{Term \ difference }{Position \ difference }}$

Common difference , $\rm d= \dfrac{-34-(-24)}{31-1}$

                                        $\rm = \dfrac{-10}{30}$

                                        $\rm = -\dfrac{1}{3}$

____________________________________

$\rm 70^{th} \ term = 31^{st} \ term +39d$

                $= \rm -34+39\times-\dfrac{1}{3}$

                $\rm = -34-13$

                $\rm = \bf -47$

____________________________________

      HOPE IT HELPS U