Question 18 and 19 plz
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we know s=n/2(2a+(n-1)d)
6/2(2a+(6-1)d)=42. (by question)
3(2a+5d)=42
2a+5d=42/3
2a+5d=13. (eq1)
a+9d/a+29d=1/3 (by question)
3a+27d=a+9d.
2a=2d
a=d.
by eq 1
2a+5a=14
7a=14
a=2
d=2 because a=d
13th term=a+12d
2+12*2
2+24
25
we know s=n/2(2a+(n-1)d)
6/2(2a+(6-1)d)=42. (by question)
3(2a+5d)=42
2a+5d=42/3
2a+5d=13. (eq1)
a+9d/a+29d=1/3 (by question)
3a+27d=a+9d.
2a=2d
a=d.
by eq 1
2a+5a=14
7a=14
a=2
d=2 because a=d
13th term=a+12d
2+12*2
2+24
25
vimal217:
sorry 26
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