posted by keith on .
i solved by factoring like this:
now i need to solve by the form x^2=k
How do I do that?
3x^2 + 5x - 12 = 0
This cannot be factored
This can be solved by completing the square or using the quadratic formula.
(3x + 4)(x - 3) = 3x^2 - 5x - 12
Does not equal 3x^2 + 5x - 12
just switch your signs
(3x-4)(x+3) = 0
so 3x-4 = 0 or x+3 = 0
x = 4/3 or x = -3
your version would give a middle term of -5x