Answers

2016-07-05T08:48:39+08:00
The common difference is 50. not sure
0
2016-07-08T12:04:29+08:00
We will use the formula Sn=n/2(a1+an)
sn=530
an=80
n=10
a1=?
d=?

*Finding value of a

530=10/2(a1+80)
530=5(a1+80)
530=5a1+400
530-400=5a1
130=5a1
a1=26

Finding the difference we use the formula an=a1+(n-1)d
80=26+(10-1)d
80=26+9d
80-26=9d
54=9d
d=6

The a1=26 an d=6

:)
2 5 2
Nice one ^_^
Thanks ~
anytime ^_^
maraming maraming salamat!
san po kinuha yung 400? sa finding the value of a1?