数学因式分解：要下面题的答案

Question

如题所述

Answer 1

(3) 3n^2-8n+4=(3n-2)(n-2).
(4) 5n^2+19n+12=(5n+4)(n+3)..
(5) 2v^2+11v+5=(2v+1)(v+5).
(6) 2n^2+5n+2=(2n+1)(n+2).
(7) 7a^2+53a+28=(7a+4)(a+7).
(8) 9k^2+66k+21=3(3k^2+22k+7)
=3(3k+1)(k+7).
(9) 15n^2-27n-6=3(5n^2-9n-2)
=3(5n+1)(n-2).
(10) 5x^2-18x+9=(5x-3)(x-3).
(11) 4n^--15n-25=(4n+5)(n-5).
(12) 4x^2-35x+49=(4x-7)(x-7).
(13). 4n^2-17n+4=(4n-1)(n-4)..
(14) 6x^2+7x-49=(3x-7)(2x+7).
(15) 6x^2+37x+6=(6x+1)(x+6).
(16) -6a^2-25a-25=-(6a^2+25a+25)
=-(2a+5)(3a+5).
(17) 6n^+5n-6=(3n-2)(2n+3).
(18) 16b^2+60b-100=4(4b^2+15b-25)
=4(4b-5)(b+5).