(5/6一3/4)÷17/16x51/8 4.8×38.7十0.3x480℅

(5/6一3/4)÷17/16x51/8 4.8×38.7十0.3x480℅ 9分之8X=6分之1x51分之16 怎么算 1/1x3+1/3x5+1/5x7+.1/49x51的简便方法 1X3分之一+3X5分之一+5X7分之一……+49X51分之一 1/1x3+1/3x5+1/5x7+.1/49x51 为什么除2 1/1x3+1/3x5+1/5x7+.+1/49x51求简便运算, 请把计算的过程写下来,并给理由〜要求：准确率,2.5X2.5X•••X2.5X0.4X0.4•••X0.4（2013个2.5） （2012个0.4101X51.8-1.25X51.8X0.8 下面公式用lingo如何表示?z=max (d1,d2,d3,d4,d5);d1=min(2*x11+10*x21+9*x31+7*x41+8*x51+12*x61+5*x71);d2=min(15*x12+4*x22+14*x32+8*x42+4*x52+4*x62+16*x72);d3=min(13*x13+14*x23+16*x33+11*x43+15*x53+6*x63+8*x73);d4=min(1*x14+15*x24+13*x34+9*x44+8 1+2x3+4x5+6x7+.50x51的和是奇数还是偶数?写出原因 1X3分之1+3X5分之1+5X7分之1+……49X51分之1咋做啊 1/1X3+1/3X5+1/5X7.+1/49X51=?1为分子,1X3为分母 1/1x3+1/3x5+1/5x7+...+1/49x51过程然后帮忙讲一下能不能帮个忙啊 1/1X3+1/3X5+1/5x7+1/7+9+…+1/49x51=? (1/1x3)+(1/3x5)+(1/5x7)+……+(1/49x51)=如题 求改lingo程序,用sets：endsetsmin=1020*2-(48.7*(x11+x12)+52.0*(x21+x22)+61.3*(x31+x32)+72.0*(x41+x42)+48.7*(x51+x52)+52.0*(x61+x62)+64.0*(x71+x72));2*x11+3*x21+x31+0.5*x41+4*x51+2*x61+x71=0;x72>=0;@gin(x11);@gin(x21);@gin(x31);@gin(x41);@gin(x51 已知数据X1,X2,...,X10的平均数为a；X11,X12,...,X50的平均数为b；X51,...,X100的平均数为c,则X1,X2,X3,...,X100的平均数为多少A.a+b+c/3 B.a+b+c/10 C.a+3b+6c/10 D.a+4b+5c/10 lingo问题求纠正.min 6x11+2x12+6x13+7x14+4x15+2x16+5x17+9x18+4x21+9x22+5x23+3x24+8x25+5x26+8x27+2x28+5x31+2x32+1x33+9x34+7x35+4x36+3x37+5x38+7x41+6x42+7x43+3x44+9x45+2x46+7x47+1x48+2x51+3x52+9x53+5x54+7x55+2x56+6x57+5x58+5x61+5x62+2x63+2x64+8x65+ 1240x3.5+124x51+1.24x1400用简便方法计算