Which of the following equations has NO real number solutions

a. 3x^2 - 5x + 1 = 0
b. 3x^2 - 5x + 4 = 0
c. -3x^2 - 11x + 4 = 0
d. -2x^2 - 3x + 1 = 0

Please help, I'm completely stuck again! :P It'll be great if you could add an explanation along with the answer :) Thank you so much guys <3 :3

You have equations of the form:

ax² + bx + 1 = 0

Such an equation has no real roots if its determinate, b² - 4ac is less than zero.

So go though all 4 equations and find the one where:

b² - 4ac < 0

Use the quadratic formula. If the discriminant is negative, there are no real solutions.