Positive & negative intervals of polynomials f(x) = (7x - 2)(52 - 8) (x + 5)(z - 6) has zeros at x=-5,x = 2/7,x =8/5, and x=6
What is the sign of f on the interval -5 <x<2/7?​

Me solve this problem, and someone clearly explain to me how to solve it.1.) use the value of the discriminant to determine if the given trinomials has 2 real solutions, 1 real solution, or no real solutions.a.  x2  − 4x  − 7 = 0b. 4r2  + 11r  − 3 = 0c. 3m2  + 7 = 0d.  t2  + 2t  + 1 = 0