McDougal Littell Algebra 2, Chapter 5, 5.2, Section 5.2, Problem 36

Okay Lets start with multiply 3 by 10 which will equal...
10X3=30
Now we have to have multiples of 30 that when add/subtracted will gives us the middle term so 17x
2x15=30 15+2 this will gives us 17. Now replace these two numbers with the middle term
3x^2+17x+10
(3x^2+2x)+(15x+10) Now take out the number that each expression is divisible by
x(3x+2)+5(3x+2) The expressions in the parentheses should match because it will only be one expression for the final equation. The second expression will be the combination of the two terms you got when you took out the number the expressions were divisible by
(3x+2)(x+5) And you got the answer!