this is an equation that is quadratic in form. so to solve th given equation we must first factor it:
n2 + n = 56n2 + n - 56 = 0( n - 7 ) ( n + 8 ) = 0equate to zeron - 7 = 0n = 7andn + 8 = 0n = - 8
so the 7th figure has 56 blocks because there are no negative nth figure
