(4.5X7.5X9.6)/(1.5X2.5X2.4)= 用简便计算

(4.5X7.5X9.6)/(1.5X2.5X2.4)= 用简便计算 巧算：1x2+2x3+3x4+4x5+5x6+6x7...+8x9 1x2+2x3+3x4+4x5+5x6+6x7+7x8+8x9+9x10+10x11 1x2+2x3+3x4+4x5+5x6+6x7+7x8+8x9= 问关于matlab解方程的问题~x是方程((0.5*X1+2*X2+3.5*X3+3*X4+5*X5+4.5*X6+6.5*X7+6*X8+7.5*X9+8*X10+0.5*X11+1.5*X12)-X14)/0.21*1.2*0.79+X15)*(27.32*(x-298)+6.226/2000*(x^2-298^2)-0.9502/(3*10^6)*(x^3-298^3))+(X2+2*X3+2*X4+3*X5+3*X6+4*X7+4*X8+4 一、利用性质、定律简算.6.7X0.8X12.5 32X1.25X0.25 9.3÷0.125÷8 32.9X37＋32.9X82-32.9X19 （4.5X7.5X9.6）÷（1.5X2.5X2.4） 计算：1/1x2+1/2x3+1/3x4+1/4x5+1/5x6+1/6x7+1/7x8+1/8x9+1/9x10. 1x2+2x3+3x4+4x5+5x6+6x7+7x8+8x9+9x10+10x11+ +nx(n+1)= 规格是1x1,2x2,3x3,4x4和5x6,6x7,7x9,8x9的木板都有足够多,拼一个17x17的正方形,要五个,至少要几块木板? 38.3x7.6+11x9.25+427x0.24 1/1x2＋1/2x3＋1/3x4＋1/4x5＋1/5x6＋1/6x7＋1/7x8＋1/8x9＝?急! 2x2/1x3+4x4/3x5+6x6/5x7+8x8/7x9+10x10/9x11+12x12/11x13 仔细看看 给50啊 Matrix dimensions must agree.x1=data(:,2);x2=data(:,3);x3=data(:,4);x4=data(:,5);x5=data(:,6);x6=data(:,7);x7=data(:,8);x8=data(:,9);x9=data(:,10);y=data(:,11);input_train=[x1,x2,x3,x4,x5,x6,x7,x8,x9];output_train=[y];minp=min(input_train);maxp=max(i 7(x-9-5-7)+0x9+1x5+2x7=y6(x-5-2-1)+15x1+14x2+13x5=y 已知x1,x2,x3,x4的平均数为5．x5,x6,x7,x8,x9的平均数为10,则这两组数据的平均数为多少? 求解最佳方案X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 一平米需要多少砖分别是：4.5X14.57.3X7.34.5X9.510X109.5X9.57.3X7.311.2X22.514X28规格,麻烦告诉我具体需要多少,如何计算,饿,这个是外墙砖~ 数学题所有的要过程3/5X2/11+2/11÷5/2 48X(1/2+5/6+3/8) 2又5/8X9.25+7又3/8X9又1/47/9÷11/8X(1/4+2/3) 7/18÷[(5/7-1/3X7/16] 请不要嫌麻烦