1+2╳3╳4+5+6╳7+8=80
1+2+3+4—5+67+8=80
12-34-56+78=0 123+-45+78=156 123+45-78=90 -12+34-56+78=44123+345-678=-210 12+23+34-56+78=91-12-23+34-56+78=21 12-23+34-56+78=45
这个算啥？→_→找作业帮呗。^_^^o^
