a/ \(-3\left(x-5\right)+6\left(x-2\right)=9\)
\(\Rightarrow-3x-\left(-3.5\right)+6x-\left(6.2\right)=9\)
\(\Rightarrow-3x+15+6x-12=9\)
\(\Rightarrow-3x+6x=9+12-15\)
\(\Rightarrow3x=6\)
\(\Rightarrow x=2\)
b/ \(4x-5\left(-3+x\right)=7\)
\(\Rightarrow4x-5.\left(-3\right)-5x=7\)
\(\Rightarrow4x+15-5x=7\)
\(\Rightarrow4x-5x=7-15\)
\(\Rightarrow-1x=-8\)
\(\Rightarrow x=8\)
c/ \(5\left(x-7\right)+10\left(3-x\right)=20\)
\(\Rightarrow5x-5.7+10.3-10x=20\)
\(\Rightarrow5x-35+30-10=20\)
\(\Rightarrow5x-10x=20-30+35\)
\(\Rightarrow-5x=25\)
\(\Rightarrow x=-5\)
d/ \(-4\left(x+1\right)+8\left(x-3\right)=24\)
\(\Rightarrow-4x-4.1+8x-8.6=3=24\)
\(\Rightarrow-4x-4+8x-24=24\)
\(\Rightarrow-4x+8x=24+24+4\)
\(\Rightarrow4x=52\)
\(\Rightarrow x=13\)
a) -3(x-5)+6(x-2)=9
<=>-3x+15+6x-12-9=0
<=>3x=6
<=>x=2
Vậy x=2
b)4x-5(-3+x)=7
<=>4x+15-5x=7
<=>-x=-8
<=>x=8
Vậy x=8
c) 5(x-7)+10(3-x)=20
<=>5x-35+30-10x=20
<=>-5x=25
<=>x=-5
Vậy x=-5
d) -4(x+1)+8(x-3)=24
<=>-4x-4+8x-24=24
<=>4x=52
<=>x=13
Vậy x=13