Question

what is 3x^2-2n-5=0
please help me!!!

Answer 1

The answer to your question is: 
It is a quadratic equation in 'x', with 'n' mistakenly typed in the second term..

Although you didn't ask for the solutions to the equation, I'm already here
so I might as well go through it and find them:

3x² - 2x - 5 = 0

In terms of the generic quadratic formula:
A = 3
B = -2
C = -5

Plug those into the quadratic formula, and you discover that

x = -1
and
x = ⁵/₃

Answer 2

$3x^2-2x-5=0$

$(3x-5)(x+1) = 0$

$3x-5=0$

$3x=5$

$x= \frac{5}{3}$

$x+1 =0$

$x=-1$

$x=-1, \frac{5}{3}$