Đáp án:
$\displaystyle \begin{array}{{>{\displaystyle}l}} 1.-5x( 1+2y-3z)\\ 2.\ 7a( 1-2b-3c)\\ 3.5a( x-5y+4)\\ 4.-12x( y+1)\\ 5.2a( ax-3ay+6)\\ 6.( 2a-b)( x+y)\\ 7.3( x-2)( a-b)\\ 8.5a( 1+2b)( x+y)\\ 9.5a^{2}( 1-3a)( x-y)\\ 10.( x-y)( a-b)\\ 11.( a-b)( x-2)\\ 12.( 7-y)( 3-2x)\\ 13.( 7-8a)( a-5)\\ 14.2( x+5)( x-y) \end{array}$
Giải thích các bước giải:
$\displaystyle \begin{array}{{>{\displaystyle}l}} 1.\ -5x-10xy-15xz=-5x( 1+2y-3z)\\ 2.\ 7a-14ab-21ac=7a( 1-2b-3c)\\ 3.\ 5ax-25ay+20a=5a( x-5y+4)\\ 4.\ 6xy-12x-18yx=-12xy-12x=-12x( y+1)\\ 5.\ 2a^{2} x-6a^{2} y+12a=2a( ax-3ay+6)\\ 6.\ 2a( x+y) -b( x+y) =( 2a-b)( x+y)\\ 7.\ 3x( a-b) -6( a-b) =3( x-2)( a-b)\\ 8.\ 5a( x+y) +10ab( x+y) =5a( 1+2b)( x+y)\\ 9.\ 5a^{2}( x-y) +15a^{3}( x-y) =5a^{2}( 1-3a)( x-y)\\ 10.\ x( a-b) -y( a-b) =( x-y)( a-b)\\ 11.\ a( x-2) +b( 2-x) =( a-b)( x-2)\\ 12.\ 7( 2x-3) -y( 3-2x) =( 7-y)( 3-2x)\\ 13.\ 7( a-5) +8a( 5-a) =( 7-8a)( a-5)\\ 14.\ 2x( x-y) -10( y-x) =2( x+5)( x-y) \end{array}$
