Question

Write the sum using summation notation, assuming the suggested pattern continues.

-9 - 3 + 3 + 9 + ... + 81

Answer 1

@amistre64 @ct3324432089

Answer 2

ok wait let me check it

Answer 3

first find out the no.of terms

Answer 4

a1=-9,d=-3-(-9)
= -3+9
=6(common difference)
next tn = -9+(n-1)6
=-9-6+6n
-15+6n
now,6n-15 =81
6n=96
n=16
now
s16= 16/2*(-9+81)
=8* 72
= 576

look babes ,its done