Răspuns :
Explicație pas cu pas:
a)15x - 15 + 8 - 12x = 9 - 2x - 8
3x - 7 = 1-2x
3x + 2x = 1+7
5x = 8
x = 8/5
b) 30- 10x + 6x + 12 = 13 + 14x - 7
-4x +42= 14x +6
-4x - 14x = 6-42
-18x = - 36
x = 36/18
x =2
c) 4x+14 +3x - 3 = 6x +18 - 18
7x + 11 = 6x
7x - 6x = 11
x = 11
[tex]\it 15(x-1)+4(2-3x)=9-2(x+4) \Rightarrow 15x-15+8-12x=9-2x-8 \Rightarrow \\ \\ \Rightarrow 3x-7=-2x+1 \Rightarrow 3x+2x=1+7 \Rightarrow 5x=8 \Rightarrow x=\dfrac{8}{5}=1,6[/tex]
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[tex]\it 2(2x+7)+3(x-1)=6(x+3)-18 \Rightarrow 4x+14+3x-3=6x+18-18 \Rightarrow \\ \\ \Rightarrow 7x+11=6x \Rightarrow 7x-6x=11 \Rightarrow x=11[/tex]