Find the product of all positive integer values of c such that 8x^2+15x+c=6x^2+7x has two real roots.
Rearrange as
2x^2 + 8x + c = 0
This will have two real roots when the discriminant > 0 .......so
8^2 - 4 (2) c > 0
64 > 8c
64 / 8 > c
So
c < 8
So...... seven positive integer values of c will work
The product of these = 7! = 5040
