Question

Clear
If the first two terms of an A.Pare -3 and 4, then what is the 21 st term
this A.P?
0 -143
O 143
O 137
O
17​

Answer 1

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If the first two terms of an A.Pare -3 and 4, then what is the 21 st term

this A.P?

$\huge\tt{\bold{\underline{\underline{Answer᎓}}}}$

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$\bold{=>First term (a)=-3}$

$\bold{=>second term (A2)=4}$

$\bold{=>D(common\: difference)=A2-a}$

$\bold{=>4-(-3)=7}$

$\bold{Now,finding \:21st \:term =a+20d}$

$\bold{=>a21=a+20d=-3+20×7=-3+140=}{\bold{\red{137}}}$

therefore,21st term is( C) 137.

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