Question

Help!

Is there alternative way in solving a arithmetic sequence?​

Answer 1

`{ \boxed{ \blue{ \tt{last \: term : l = a + (n - 1)d}}}} \\ \\ { \boxed{ \green{ \tt{sum : s = (n)/(2) (2a + (n - 1)d}}}} \\ or\\ { \boxed{ \tt{ \red{sum : s = (n)/(2) (a + l)}}}} \\ { \bf{s \: is \: sum }} \\ { \bf{ l \: is \: last \: term}} \\{ \bf{ n \: is \: number \: of \: terms}} \\{ \bf{ d \: is \: common \: difference}} \\ \\ { \underline{ \blue{ \tt{becker \: jnr}}}}`