1. The first step is to factorise the first term x2.2. The next step is to factorise the third term.3. The 3rd step is to add the factors in order to get the middle term. Factorising Quadratic Trinomial Expressions Drag and drop So the factors whose product is 20 and addition is 9 are The factors of x2 are (x) (x) ? 4 x 5 ? Factorise x2 + 9x + 20 The factors of 20 are 1 x 2 x 4 x ? 10 ? 5 ? 20 ? Drag and drop So the factors are Factorise x2 + 9x + 20 +4 ? X 4X X2 X ? (x+5)(x+4) ? 5X 20 +5 ? Drag and drop So the factors whose product is 20 and addition is -9 are The factors of x2 are (x) (x) ? Factorise x2 - 9x + 20 - 4 x - 5 ? The factors of 20 are 1 x 2 x 4 x -1 x-2 x -4 x ? -10 ? -5 ? 20 ? 10 ? 5 ? -20 ? Drag and drop So the factors are Factorise x2 - 9x + 20 -4 ? X -4X X2 X ? (X-5)(X-4) ? -5X 20 -5 ? Factors of 20 1 x 20 2 x 10 4 x 5-1 x - 20-2 x - 10-4 x - 5 Drag and drop So the factors whose product is - 20 and addition is -1 are The factors of x2 are (x) (x) ? - 5 x 4 ? Factorise x2 - x - 20 The factors of - 20 are -1 x -2 x -4 x -5 x -10 x -20 x 2 ? 4 ? 1 ? 20 ? 10 ? 5 ? Drag and drop So the factors are Factorise x2 - x - 20 +4 ? X 4X X2 X ? (X-5)(X+4) ? -5X -20 -5 ? Factors of - 20 -1 x 20-2 x 10-4 x 5-5 x 4-10 x 2-20 x 1 Drag and drop So the factors whose product is - 20 and addition is +1 are The factors of x2 are (x) (x) ? - 4 x 5 ? Factorise x2 + x - 20 The factors of - 20 are -1 x -2 x -4 x -5 x -10 x -20 x 2 ? 4 ? 1 ? 20 ? 10 ? 5 ? Drag and drop So the factors are Factorise x2 + x - 20 - 4 ? X - 4X X2 X ? (X - 4)(X + 5) ? + 5X - 20 + 5 ? Factors of - 20 -1 x 20-2 x 10-4 x 5-5 x 4-10 x 2-20 x 1 |