72+83+7512-514-51176+152+71+151367-74-73+3241517+8712+321741+131+41+323-91-981516-715-2
8114+95+1171517-(152+75)127-193+125-19697+74-73119-(94+112)98-(98-31)198-(198-92)751+115+72+1161219+(85+125)74-61+73-185523+6310+313+2
82+(738-2
82)-5343
825+249+1591514+159-21410-229-3794
375+659-459+55810314-(2314+3
9)1-112-11195+(43+21)31+54-7397+74-73解方程1519+x=512x-119=7334=x+0
25x-65=61x+3
5×2=120
375+5x=203894+(x-21)=3x+3914=5
375x-(87-41)=653x-43=411519+X=512X+(95-91)=87X-(127-41)=65154+(X-21)X-92=652X-71=76315-x=3
2x-(87-41)=65154+(x-21)=291+85+321-92-411310-52+21127-181-9261+75+65247+83-12543+63-8585-(81+91)65-41+3132+43-10376+(54-103)1-(72+51)1-(43-52)34-(52+103)75+41-1492718给下面的分数约分3624754551175719241620359113将下列各组分数通分137和915193和576分数乘除法简便运算专题练习(1)(89+427)×3×9(2)(38-38)×615127