Question

Poderia alguem me ajudar a resolver esta conta? Obrigada!!!! (é a conta número 7)

Answer 1

$P.A~(500,...,2150)$

$a_{1}=500\\a_{12}=2150$
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$a_{n}=a_{1}+(n-1)r\\a_{12}=a_{1}+(12-1)r\\a_{12}=a_{1}+11r\\2150=500+11r\\2150-500=11r\\11r=1650\\r=1650/11\\r=150$

Achando o décimo termo da P.A:

$a_{n}=a_{1}+(n-1)r\\a_{10}=a_{1}+(10-1)r\\a_{10}=a_{1}+9r\\a_{10}=500+9*150\\a_{10}=500+1350\\a_{10}=1850}$

Letra C