Question

determine o vigésimo termo de P.A (1, 8, 15....)​

Answer 1

Resposta:

134

Explicação passo-a-passo:

PA: an = a1 + (n – 1)r

a1 = 1

r = a2-a1 = 8-1 = 7

n = 20

a20 = 1 + (20-1)7

a20 = 1 + (19)7

a20 = 1 +  133

a20 = 134

Answer 2

$\mathsf{a_n=a_1+(n-1)\cdot r }$

$\mathsf{a_{20}=1+(20-1)\cdot7 }$

$\mathsf{a_{20}=1+19\cdot7 }$

$\mathsf{ a_{20}=1+ 133}$

$\boxed{\boxed{\mathsf{a_{20}=134 }}}$