Differentiate f(x) = (3x + 5)(4x - 7)

A good way to approach this question is to first expand the brackets . This gives 12x² - 21x + 20x - 35 (remember to take the negative seven into account). We can then simplify this to give 12x² - x - 35 . Finally, we use the standard rules for differentiation to give f'(x) = 24x - 1