factorise: 3x^2+13x-30
(3x-5)(x+6)factors of 90 (3x30): 1x90, 6x15, 9x10, 5x18and add up to 13 can only be 5 and 1818-5=13 5/3 or 18/3=6 and 5x6=30so must be (3x-5)(x+6) and check by expanding with FOIL method
(3x-5)(x+6)factors of 90 (3x30): 1x90, 6x15, 9x10, 5x18and add up to 13 can only be 5 and 1818-5=13 5/3 or 18/3=6 and 5x6=30so must be (3x-5)(x+6) and check by expanding with FOIL method
