Question

1. Evaluate the discriminant for each equation, then use it to determine the nature of the roots for each quadratic equation.

(a) x^+4x+5=0

(b) x^-4x-5=0

(c) 4x^2+20x+25=0

Answer 1

Given the quadratic equation ax^2 + bx + c = 0, the coefficients of x^2, x and 1 are a, b and c respectively.  

(a) and (b) are not valid quadratics, because they omit the exponent 2.   Rewrite these as comments within your original post, please.

(c) 4x^2+20x+25=0:  Here, a = 4, b = 20 and c = 25.