(3.91-3又7分之3+6.09-6又4/7)x(-1)2013次方+(1除2/3-1.5)x2013
(3.91-3又7分之3+6.09-6又4/7)x(-1)2013次方+(1除2/3-1.5)x2013
(3.91-3又7分之3+6.09-6又4/7)x(-1)2013次方+(1除2/3-1.5)x2013
解:原式=(3.91+6.09-3-3/7-6-4/7)*(-1)+(1.5-1.5)^2013
=(10-10)*(-1)+0
=0+0
=0

(3.91-3又3/7+6.09-6又4/7)x(-1)2009次方+(1除2/3-1.5)x2009怎么算
(3.91-3又3/7+6.09-6又4/7)x(-1)2009次方+(1除2/3-1.5)x2009
=(3.91+6.09-3又3/7-6又4/7)x(-1)+(1.5-1.5)x2009
=(10-10)x(-1)+0x2009
=0
(3.91+3又3/7+6.09+3又4/7)x(2又1/8-1.125)+(1除以2/3-1.5)x6.04
(3.91+3又3/7+6.09+3又4/7)x(2又1/8-1.125)+(1除以2/3-1.5)x6.04
=(3.91+6.09+3又3/7+3又4/7)x(1+1又1/8-1.125)+(3/2-1.5)x6.04
=17
“(3.91-24/7+6.09-46/7)*(-1)的2009次方+(1/2/3-1.5)*2009 计算
=[(3.91+6.09)-(24/7+46/7)]*(-1)+0*2009
=(10-10)*(-1)+0
=0*(-1)
=0
(3.91+3又3/7+6.09+6又4/7)*(2又1/8-1.125)
(3.91+3又3/7+6.09+6又4/7)*(2又1/8-1.125)
=(3.91+24/7+6.09+46/7)*(17/8-9/8)
=(10+10)*1
=20
(3.91+3又7分之3+6.09+6又7分之4)*(2又8分之1-1.125)+(1/3分之2-1.5)*6.04简便计算
(3.91+3又7分之3+6.09+6又7分之4)*(2又8分之1-1.125)+(1/3分之2-1.5)*6.04
=(3.91+6.09+3又7分之3+6又7分之4)*(2.125-1.125)+(3/2-1.5)*6.04
=(10+10)*1+0*6.04
=20
计算: (1)(-4/3)X(-2/1)除(-2又4/1) (2) -6除(-0.25)X24/11 (3) (-3/2)除3/1(-2/1)
(1)(-4/3)X(-2/1)除以(-2又4/1)
= 8/3÷(-4/9)
=-8/3×9/4
=-6/1
(2) -6除以(-0.25)X24/11
=6×4×24/11
=11
(3) (-3/2)除以3/1×(-2/1)
=3/2×3×2/1
=1
(3.91+3又3/ 7+6.09+6又4/ 7)*(2又1/ 8-1.125)=? 说明简便方法!
3又3/ 7+6又4/ 7=10 3.91+6.09=10 1/ 8=0.125 所以2又1/ 8-1.125=1 即原式=(10+10)/1=20
若x1,x2,x3,……,x2013的方差为3,则3(x1-2),3(x2-2),3(x3-2),……3(x2013-2)的方差
由方差的性质可以知道,
若Dx=m,
则D(ax+b)=a² *m
那么在这里,
x1,x2,x3,……,x2013的方差为3
那么显然
3(x1-2),3(x2-2),3(x3-2),……3(x2013-2)的方差
为3² *3=27