(1)M+x²+3x+7=15x²+2x-4
M=15x²+2x-4-(x²+3x+7)
=15x²+2x-4-x²-3x-7
=14x²-x-11
(2)这个问题的正确结果:
14x²-x-11+(x²-3x+7)
=14x²-x-11+x²-3x+7
=15x²-4x-4
(1)M+x²+3x+7=15x²+2x-4
M=15x²+2x-4-(x²+3x+7)
=15x²+2x-4-x²-3x-7
=14x²-x-11
(2)这个问题的正确结果:
14x²-x-11+(x²-3x+7)
=14x²-x-11+x²-3x+7
=15x²-4x-4