In order to divide polynomials ('many terms'), it is best to factor the dividend and divisor into similar terms, when possible.
So let's see if we can get the larger one into "2x+5".
6x^2 + 23x + 20 = (2x+5)×(3x+4)
So now we have: (2x+5)×(3x+4) ÷ 2x+5
= 3x+4, the two "2x+5" terms cross each other out, since one is numerator and the other denominator because anything divided byb itself is 1
So final answer: the quotient = 3x+4
I hope that makes sense! :)