Question

Find the arithmetic sum 52 + 59 + 66 + … + 248.

S29 = 4,350
S28 = 4,200
S30 = 4,500
S27 = 4,050

Answer 1

do you know the formula to find arithmetic sum ??

Answer 2

no

Answer 3

formula to find arithmetic sum
\[\huge\rm s_n = \frac{ n(a_1+a_n) }{ 2 }\]
a_1=first term
a_n = last term
n = total number of terms
because you don't know how many terms are there so first step is to find n
to find n
apply this formula \[\huge\rm a_n = a_1 + (n-1)d\]

Answer 4

replace variables by their values and solve for n
\[\large\rm a_n = a_1 +(n-1)d\]
d = common difference
do you know how to find common difference from that sequence ?

Answer 5

in your sequence, \((\color{red}{52} + 59 + 66 + … + \color{blue}{248})\) your \(\color{blue}{a_n = 248}\) and your \(\color{red}{a_1 = 52}\)

Answer 6

To find d, subtract \(a_3 - a_2 = 66-59 =~? ~,~ a_2-a_1 = 59-52=~?\)
\[a_n=~?\]\[a_1=~?\]\[d=~?\]
Use those two values in the equation @Nnesha provided for you to find \(n\). \(a_n=a+1+(n-1)d\)