When multiplying binomials, such as (x + 3)(x + 4) you can multiply each term of the first binomial times the terms of the second binomials. The product of (x + 3)(x + 4) is x * x + x * 4 + 3 * x + 3 * 4 which becomes x² + 3x + 4x + 12. The like terms should be combined so the answer becomes x² + 7x + 12.
(x + 1)(x + 12) = x² + 12x + 1x + 12 which becomes x² + 13x + 12
(x - 1)(x + 12) = x² + 12x + (-1)x + (-12) which becomes x² + 11x - 12
(x - 1)(x - 12) = x² + (-12x) + (-1x) + 12 which becomes x² - 13x + 12
(x + 6)(x - 8) = x² + (-8x) + 6x + (-48) which becomes x² - 2x - 48
For each problem you need to multiply the binomials and combine like terms. Strive to be able to accomplish the problems with ease and then strive to increase your speed. Good luck and enjoy the challenge!