Question

Seja a PA (-4, x, y, 14, z), qual o valor de x?

Answer 1

$\large\boxed{\begin{array}{l}\rm a_4=14\\\rm a_1=-4\\\rm a_4=a_1+3r\\\rm 14=-4+3r\\\rm 3r=14+4\\\rm 3r=18\\\rm r=\dfrac{18}{3}\\\\\rm r=6\\\rm x=-4+6=2\end{array}}$