Ok so If (4x+3)(-2x-5) you have to times 4x to everything on the other side so you times 4x to -2x to get -8x^2 and then you have to times 4x times -5 to get -20x then it is -8x^2-20x so that is what you have so far then you have to times 3 on everything on the other side so you times 3 to -2x to get -6x and you time 3 to -5 to get -15 and that is -6x-15 then you put the two equations back together so -8x^2-20x-6x-15 then you combine like terms so -20x +-6x so it is -26x so the final result is -8x^2-26x-15
i hope i could of helped