Câu 1:
a: 4x-2=x+5
=>4x-x=2+5
=>3x=7
=>\(x=\dfrac{7}{3}\)
b: -2x-5=5x-7
=>-2x-5x=-7+5
=>-7x=-2
=>\(x=\dfrac{-2}{-7}=\dfrac{2}{7}\)
c: \(2\left(2x-1\right)=5\left(x-1\right)\)
=>\(5x-5=4x-2\)
=>5x-4x=-2+5
=>x=3
d: \(5\left(1-3x\right)=-2\left(4x+5\right)\)
=>\(-15x+5=-8x-10\)
=>-7x=-15
=>\(x=\dfrac{15}{7}\)
Bài 2:
a: \(\dfrac{x}{2}-\dfrac{1}{5}=2-\dfrac{x}{3}\)
=>\(\dfrac{x}{2}+\dfrac{x}{3}=2+\dfrac{1}{5}\)
=>\(x\cdot\dfrac{5}{6}=\dfrac{11}{5}\)
=>\(x=\dfrac{11}{5}:\dfrac{5}{6}=\dfrac{66}{25}\)
b: \(1-\dfrac{x+5}{3}=\dfrac{3\left(x-1\right)}{4}\)
=>\(\dfrac{12-4\left(x+5\right)}{12}=\dfrac{9\left(x-1\right)}{12}\)
=>12-4x-20=9x-9
=>-4x-8=9x-9
=>-4x-9x=-9+8
=>-13x=-1
=>\(x=\dfrac{1}{13}\)
c: \(\dfrac{6\left(x-2\right)}{7}-12=\dfrac{2\left(x-7\right)}{3}\)
=>\(\dfrac{18\left(x-2\right)}{21}-\dfrac{336}{21}=\dfrac{14\left(x-7\right)}{21}\)
=>18x-36-336=14x-98
=>18x-372=14x-98
=>4x=-98+372=274
=>x=274:4=68.5
d: \(\dfrac{7-2x}{2}-\dfrac{2}{5}\left(2-x\right)=1\dfrac{1}{4}\)
=>\(\dfrac{7-2x}{2}+\dfrac{2\left(x-2\right)}{5}=\dfrac{5}{4}\)
=>\(\dfrac{10\left(7-2x\right)+8\left(x-2\right)}{20}=\dfrac{25}{20}\)
=>70-20x+8x-16=25
=>-12x+54=25
=>-12x=25-54=-29
=>x=29/12
