Question

Fill in the blank

$\begin{array}{ccc}6& 9& 135\\ 5& 7& 76\\ 8& 11& ....\end{array}$

Answer 1

The third number in each row is the difference between the cube of the first number and the square of the second number.
Formula : $a^3-b^2=c$
$6^3=216;9^2=81;216-81=135$
$5^3=125;7^2=49;125-49=76$
$8^3=512;{11}^2=121;512-121=391$