5b^2 - 14b - 3 = 0

This is what I did

14 = 14^2 - 4 (5)(-3) / 2(5)

14= 196 + 60 / 10

14= 256 / 10

How do I get the answer?

12x^2 - 5x = 2

I subtracted 2 and got

12x^2 - 5x - 2 = 0

5= 5^2 - 4 (12)(-2) / 2(12)

5= 25 + 96 /24

How do I get the answer?

Thanks