Factor the expression. If the expression can't be factored, say so. Show all work.
Example: 3x^2-11x+10 (equation in the form ax^2+bx+c)
_*_=30
_+_=-11
Center term is split: 3x^2-5x-6x+10
Group the pairs of terms: 3x^2-5x-6x+10
factor: x(3x-5)-2(3x-5)
factor: (3x-5)(x-2)
1. 4x^2-15x+9 2. 6x^2-13x-28 3.10x^2+29x+10
4. 9x^2+24x+16 5. -12x^2+27 6. 12x^2-40x-32
7. -15x^2+3x+12 8. 6x^3-5x^2+x 9. 3x^3-7x^2+x
10. 4x^4+12x^3+9x^2 11. 24x^4+18x^3-27x^2
12. 72x^3-228x^2+140x 13. x^4-81
14. 2x^4+5x^2+3 15. 6x^4-9x^2+3