Question

a) Solve x(x + 1) = 110, if x € N​

Answer 1

$x(x + 1) = 110 \\ {x}^{2} + x = 110 \\ x {}^{2} + x - 110 = 0 \\ {x}^{2} + 11x - 10x - 110 = 0 \\ x(x + 11) - 10(x + 11) = 0 \\ (x + 11)(x - 10) = 0 \\ x = - 11,10$