Question 1041861
the number is x and as I understand the question, 7x is added to the number, x, squared.  The result is negative.
7x+x^2<0; x(7+x)<0.  x=-7, and x=0 are the points where the function equals 0.
This quadratic equation is x^2+7x+0, and where that is less than 0 are possible numbers
any number in the interval (-7,0) will suffice, if the question is interpreted properly.
-5: -5(7)=-35 and (-5)^2=25. That sum is negative.
{{{graph(300,300,-10,10,-10,10,x^2+7x)}}}