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{ -5 ; 1 ;3 ;9 } , tick nha

Mình nhầm = 3445

a) 4(x-1)-(3x+2)=16 b)7(x-5)+5(15-x)=130

<=>4x-4-3x-2=16 <=>7x-35+75-5x=130

<=>x-6=16 <=>2x+40=130

<=>x=22 <=>2x=90

<=>x=45

c) 30(x- 2 ) - 6( x - 5 ) - 22x = 100 d) x-17+x=x-23

<=>30x-60-6x+30-22x=100 <=>2x-x=-23+17

<=>2x-30=100 <=>x=-6

<=>2x=130

<=>x=65

CuO + H2 to-----> Cu + H2O

0,15----> 0,15-------->0,15

nCuO=m/M=12/80= 0,15 (mol)

mCuO=M.n=64.0,15=9,6(g)

HCuO=(mcupư/mcudư).100%=(6,6/9,6).100%=68.75%