有理数的加减法.1-4+3-0.5,-2.4+3.5-4.6+3.5,(-7)-(+5)+(-4)-(-10),3/4-2/7+(-1/6)-(-2/3).要用地等式,和加法结合律来写地等式 55555大虾帮帮忙吧就这几道,过几天开学了~
有理数的加减法.1-4+3-0.5,-2.4+3.5-4.6+3.5,(-7)-(+5)+(-4)-(-10),
3/4-2/7+(-1/6)-(-2/3).要用地等式,和加法结合律来写地等式 55555大虾帮帮忙吧就这几道,过几天开学了~
1-4+3-0.5
解 原式=1+3-(4+0.5)
=4-4.5
=-0.5
-2.4+3.5-4.6+3.5
解 原式=2x3.5-(2.4+4.6)
=7-7
=0
(-7)-(+5)+(-4)-(-10)
解 原式=10-(7+5+4)
=10-16
=-6
3/4-2/7+(-1/6)-(-2/3)
解 原式=3/4-2/7-1/6+2/3
=3/4+2/3-(2/7+1/6)
=17/12-19/42
=119/84-38/84
=27/28
3\4-2\7+(-1\6)-(-2\3)
=3\4-2\7-1\6+2\3
=9\12-2\7-2\12+8\12
=15\12-2\7
=105\84-24\84
=81\84=27\28
1. 1-4+3-0.5=1+3-4-0.5=4-4-0.5=-0.5
2. -2.4+3.5-4.6+3.5=-(4.6+2.4)+(3.5+3.5)=7-7=0
3. (-7)-(+5)+(-4)-(-10)=-7-5-4+10=-6
4. 3/4-2/7+(-1/6)-(-2/3)=3/4-2/7-1/6+2/3=3/4-2/7+(2/3-1/6)=(3/4+1/2)-2/7=5/4-2/7=27/28
1. 0.5 2, 0 3, -6
1-4+3-0.5=1+3-(4+0.5)=4-4.5=-0.5
-(2.4.+4.6)+3.5+3.5=-7+7=0
-7-5-4+10=-16+10=-6
1-4+3-0.5
=(1+3)+[-4+(-0.5)]
=4+(-4.5)
=-(4.5-4)
=-0.5
-2.4+3.5-4.6+3.5
=[-2.4+(-4.6)]+(3.5+3.5)
=-7+7
=0
(-7)-(+5)+(-4)-(-10)
=(-7)+(-5)+(-4)+10
=-16+10
=-(16-10)
=-6
3/4-2/7+(-1/6)-(-2/3)
=3/4+(-2/7)+(-1/6)+2/3
=(3/4+2/3)+[-2/7+(-1/6)]
=17/12+(-19/42)
=17/12-19/42
=119/84-38/84
=27/28
-0.5,,,0,,,-6,,,27/28
1-4+3-0.5=(1+3)+[-4+(-0.5)]=4+(-4.5)=-(4.5-4)=-0.5-2.4+3.5-4.6+3.5=[-2.4+(-4.6)]+(3.5+3.5)=-7+7=0(-7)-(+5)+(-4)-(-10)=(-7)+(-5)+(-4)+10=-16+10=-(16-10)=-63/4-2/7+(-1/6)-(-2/3)=3/4+(-2/7)+(-1/6)+2/3=(3...
3/4-2/7+(1/6)-(-2/3)=0.5