Question

Determine o centesimo termo de uma PA, sabendo que primeiro termo vale 3 e sua razao vale −5.​

Answer 1

Explicação passo-a-passo:

$</strong><strong>a_</strong><strong>{n} = </strong><strong>a_</strong><strong>{</strong><strong>1</strong><strong>}</strong><strong> + (n - 1) \times r \\ </strong><strong>a_</strong><strong>{</strong><strong>100</strong><strong>} = 3 + (100 - 1) \times - 5 \\ </strong><strong>a_</strong><strong>{</strong><strong>100</strong><strong>} = 3 + 99 \times - 5 \\ </strong><strong>a_</strong><strong>{</strong><strong>100</strong><strong>} = 3 + ( - 495) \\ </strong><strong>a_</strong><strong>{100} = 3 - 495 \\ \red{ \boxed{ \boxed{</strong><strong>a_</strong><strong>{100} = - 492}}}$