-4(1/2x-2)+1/3(6x-9)
=-2x+8+2x-3
=5
3n-[5n+(3n-1)]
=3n-5n-3n+1
=-5n+1、
若M=2p-3,N=3-5p.求:1、-2M+N;
2、M-3N.
-2M+N=-2[2P-3]+3-5P=-4P+6+3-5P=-9P+9
M-3N=2P-3-3[3-5P]=2P-3-9+15P=17P-12
-4(1/2x-2)+1/3(6x-9)
=-2x+8+2x-3
=5
3n-[5n+(3n-1)]
=3n-5n-3n+1
=-5n+1、
若M=2p-3,N=3-5p.求:1、-2M+N;
2、M-3N.
-2M+N=-2[2P-3]+3-5P=-4P+6+3-5P=-9P+9
M-3N=2P-3-3[3-5P]=2P-3-9+15P=17P-12