3,5:(-5/2)=35/10*(-2/5)=-7/5=-1,4
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(-3)*(-7)+(-4):(-2)=21+2=23
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-2/3*8*(-3/9)*9=(-2/3*(-3/9))*9*8=2/9*9*8=2*8=16
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(-4)*(-1 1/3)*(2x-8 1/2)=0
2x-8 1/2=0
2x=8 1/2
x=17/2*1/2
x=17/4
x=4 1/4
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x+2x+....10x=5500
55x=5500
x=5500:55
x=100
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