Can someone show me how to do the following 5x^2-5x-30=0

Ooh, quadratic equations!
alright, you see that zero at the end right?
that means you are trying to find the two factors
I'll write out the equation on paper to show you

take note of the signs in b and c
(ax²+bx+c)
because 5x is a negative (-5x), when you factor it out, the two, when multiplied together, should be negative. and because 30 is negative, the numbers will have two different signs. in other words, one will be positive and one will be negative.
now that that's cleared, we need to find all of the multiples of 30
there is:
30×1
15×2
10×3
and 6×5
of all of them, 10 and 3 would give you the -5 needed in -5× since one of them are going to be multiplied times 5
now let's factor it:
(5x+10)(x-3)
finally, divide everything
I wrote everything down for you to see