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Rezolvati ecuatia in multimea R:
a) 3x+7=x-2
b) 8x-(3x+1)=9
c) 5(x-3)-2(x-7)=7-7(2x+6)
d) 5(8x-1)-7(4x+1)=9-8(7-4x)
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Răspuns :

a) 3x+7=x-2
3x-x=-2-7
2x=-8
x=-4
b)8x-(3x+1)=9
5x=10
x=2
c)5(x-3)-2(x-7)=7-7(2x+6)
5x-15-2x+14=7-14x-42
5x-2x+14x=-42+15-7
17x=-34
x--2
d)5(8x-1)-7(4x+1)=9-8(7-4x)
40x-5-28x-7=9-46+32x
40x-32x-28x=9-46+5+7
-20x=-25
x=1,25

Raul19


a)3x+7=x-2 => 3x-x+7+2=0 =>  ca 2x= -9 =>  ca x= - 9/2

b)8x-3x-1=9 => ca 5x=10 => x=2

c)5x-15-2x+14=7-14x-42 => 3x-1=-35-14x=> 17x=-34 => x=-34/17 =>   x=-2

d) 40x-5-28x-7=9-56+32x => 12x -12 = -47+32x => -20x =-35 => x = 35/20 => x= 7/4.

 

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