[tex] > resolucao \\ \\ \geqslant progressao \: \: aritmetica \\ \\ r = a2 - a1 \\ r = 10 - 2 \\ r = 8 \\ \\ > 20 \: termo \: da \: pa \: \\ \\ an = a1 + (n - 1)r \\ an = 2 + (20 - 1)8 \\ an = 2 + 19 \times 8 \\ an = 2 + 152 \\ an = 154 \\ \\ = = = = = = = = = = = = = = = \\ \\ \\ r = a2 - a1 \\ r = - 1 - 1 \\ r = - 2 \\ \\ > 7 \: termo \: da \: pa \\ \\ \\ an = a1 + (n - 1)r \\ an = 1 + (7 - 1) - 2 \\ an = 1 + 6 \times ( - 2) \\ an = 1 + ( - 12) \\ an = 1 - 12 \\ an = - 11 \\ \\ \\ \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \geqslant \leqslant \geqslant \geqslant [/tex]
