Math, asked by Akhilkumar01, 1 year ago

1. which term is -81 in the A.P:- 21,18,15,..................

A) 31st B) 35th C) 34th D) 37th

2. The number of rows is there in the flower bed if 23 rose plants in the 1st row, 21 in the second row, 19 in the 3rd and so on there are 5 5 rose plants in the last row.

A) 9 B) 10 C) 8 D) 11

Answers

Answered by pratik3420
1
an=-81
a+(n-1)d= -81
21+(n-1)(-3)= -81
21-3n+3= -81
24-3n= -81
-3n= -81-24=-105
n= -105/-3=35
ans is option b
2)
an=a+(n-1)d
5=23+(n-1)-2
5=23+2-2n
-2n=5-25=-20
n=10

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Answered by Anonymous
1
hii dear here is your answer.........

1). An=-81
◆a1=21
◆d=18-21=-3
◆An=a+(n-1)d
◆-81=21+(n-1)-3
◆]-81-21=(n-1)-3
◆-102=(n-1)-3
◆-102/-3=(n-1)
◆34=(n-1)
◆n=35th term is -81

2)a=23
d=21-23=-2
An=55
An=a+(n-1)d
5=23+(n-1)-2
5-23=(n-1)-2
-18/-2=(n-1)
9=(n-1)
n=10
so B is correct

hope it helps you☺️☺️☺️

Akhilkumar01: Your second sum is wrong bro.............
Anonymous: bro plz check question again
Akhilkumar01: Once see it.....
Akhilkumar01: bro it's not 55 it's 5 only...
Anonymous: oo wow i just given the idea how to do and he do
Akhilkumar01: uh what.....what r u saying....
Akhilkumar01: plz accept my frnd request...
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