Question

calcule o 22° termo da p.a sabendo que o 1° termo é 9 e a razão é. 7​

Answer 1

$> resolucao \\ \\ \geqslant progressao \: \: aritmetica \\ \\ an = a1 + (n - 1)r \\ an = 9 + (22 - 1)7 \\ an = 9 + 21 \times 7 \\ an = 9 + 147 \\ an = 156 \\ \\ \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \geqslant$

Answer 2

$\large\boxed{\begin{array}{l}\sf a_1=9;~r=7;~a_{22}=\,?\\\\\sf a_n=a_1+(n-1)r\\\\\sf a_{22}=9+(22-1)7\\\\\sf a_{22}=9+(21)7\\\\\sf a_{22}=9+147\\\\\sf a_{22}=156~\checkmark\end{array}}$