Polynomials: Factoring by Grouping
Factor the following polynomials into binomials by grouping:
- $2x^2+6x+7x+21 \rightarrow \mathbf{(2x+7)(x+3)}$
- $3x^2-9x-8x+24 \rightarrow \mathbf{(3x-8)(x-3)}$
- $4x^2-28x+12x-84 \rightarrow \mathbf{(4x+12)(x-7)}$
- $2x^2+26x-3x-39 \rightarrow \mathbf{(2x-3)(x+13)}$
- $16x^2+48x-14x-42 \rightarrow \mathbf{(8x-7)(2x+6)}$
- $x^3-3x^2-4x+12 \rightarrow \mathbf{(x^2-4)(x-3)}$
- $x^3+2x^2+3x+6 \rightarrow \mathbf{(x^2+3)(x+2)}$
- $2x^3+2x^2-2x-2 \rightarrow \mathbf{(2x^2-2)(x+1)}$
- $3x^3+27x^2-x-9 \rightarrow \mathbf{(3x^2-1)(x+9)}$
- $2x^5-4x^4-3x+6 \rightarrow \mathbf{(2x^4-3)(x-2)}$