Question

find the 21 terms of tge following AP 2,4,6,8......​

Answer 1

$\huge \text{Answer:}$

2,4,6,8,10,... are in A.P

First term=a=2

Common differenced=4−2=2

nth term=tn=a+(n−1)d

tn=2+(n−1)2=2+2n−2=2n

∴nth term is 2n

Answer 2

${\huge{\bold{\purple{\bigstar{\boxed{\bf{Answer}}}}}}}$

${\bold{\blue{\boxed{\bf{Given}}}}}$

• first term = a = 2
• common diff. = d = 2
• no. of times =n= 21

${\bold{\blue{\boxed{\bf{To\:find}}}}}$

• $\bold{a_{21}}= ???$

${\bold{\blue{\boxed{\bf{ Formulae\:used }}}}}$

• $\bold a_n = a + (n-1)d$

${\bold{\blue{\boxed{\bf{ Formulae\:used }}}}}$

$a_{21} = 2 + (21 -1)\times 2$

$a_{21} = 2 + 20 \times 2$

$a_{21} = 2 + 40$

$a_{21} = 42$

${\bold{\blue{\boxed{\boxed{\bf{a_{30} = 42 }}}}}}$

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