The difference between the roots of the quadratic equation x2+x+c=0 is 6. find c.

We have that

Let y be the first root, then y - 6 will be the second one. Since both roots make the quadratic equation equal to 0, we have that:

Solve for y:

Plug in y = 5/2 into original quadratic equation and solve for c:

So, the answer is c = -35/4