When I am expanding brackets I use the acronym FOIL and simplify. You begin by multiply the first term (F) in each bracket, followed by multiplying the outside terms (O), then the inside terms (I) and finally the last terms (L) in each bracket. Once the brackets have been expanded, it might be possible to simplify this expression. Answers should always be left in the simplest form.(3x-7)(5x+6)=3x(5x)+3x(6)+(-7)(5x)+(-7)(6)=15x2+18x-35x-42=15x2-17x-42