The correct answer for b^2 - 4ac (also known as the discriminant) should be 57 or answer C.
You first must solve the equation for 0.
1 = 2x2 + 7x ---> subtract 1 from each side
0 = 2x^2 + 7x - 1
Now we can find a as the coefficient of the x^2 term, b as the coefficient for the x term an c as the number at the end.
a = 2
b = 7
c = -1
Now we can plug these values in for b^2 - 4ac
b^2 -4ac
(7)^2 - 4(2)(-1)
49 + 8
57
