来自李慷的问题
如果M=-12p+3q,N=3q-5p,那么M+N=______,M-2N=______.
如果M=-12p+3q,N=3q-5p,那么M+N=______,M-2N=______.
1回答
2020-03-10 08:39
如果M=-12p+3q,N=3q-5p,那么M+N=______,M-2N=______.
如果M=-12p+3q,N=3q-5p,那么M+N=______,M-2N=______.
∵M=-12p+3q,N=3q-5p,
∴M+N=(-12p+3q)+(3q-5p)
=-12p+3q+3q-5p
=-17p+6q,
M-2N=(-12p+3q)-2(3q-5p)
=-12p+3q-6q+10p
=-2p-3q,
故答案为:-17p+6q,-2p-3q.