Question

acha o a⁴²(quadragesimo segundo ) termo da p.a em que o primeiro termo e igual a-23 e a razao e igual a -7​

Answer 1

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

$a_{42}=-23+(42-1)\cdot(-7)$

$a_{42}=-23+(41)\cdot(-7)$

$a_{42}=-23-287$

$\red{\boldsymbol{ a_{42}= -310}}$

Answer 2

$> \: resolucao \\ \\ \geqslant \: progressao \: \: aritmetica \\ \\ a1 = - 23 \\ r = - 7 \\ \\ = = = = = = = = = = = = = = = \\ \\ > \: o \: 42 \: termo \: da \: pa \\ \\ an = a1 + (n - 1)r \\ an = - 23 + (42 - 1) - 7 \\ an = - 23 + 41 \times ( - 7) \\ an = - 23 + ( - 287) \\ an = - 23 - 287 \\ an = - 310 \\ \\ \\ \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \geqslant$