Question

mọi người giải giúp mình bài 3 với

Answer 1

a: 3(x-3)+4(x-2)=x-5

=>3x-9+4x-8=x-5

=>7x-17=x-5

=>6x=12

hay x=2

b: \(\Leftrightarrow x^2+2x-3x+9=x^2-7\)

=>9-x=-7

hay x=16

c: \(\Leftrightarrow x^2-x-2+3x-3-x^2+x=x-3\)

=>3x-5=-3

=>3x=2

hay x=2/3

d: \(\Leftrightarrow x^2-2x+1-x^2+4=3x-4\)

=>-2x+5=3x-4

=>-5x=-9

hay x=9/5

Answer 2

a, \(3x-9+4x-8=x-5\Leftrightarrow6x=-5+17=12\Leftrightarrow x=2\)

b, \(x^2+2x-3x+9=x^2-7\Leftrightarrow-x=-16\Leftrightarrow x=16\)

c, \(x^2-x-2+3x-3-x^2+x=x-3\Leftrightarrow2x=2\Leftrightarrow x=1\)

d, \(x^2-2x+1-x^2+4=3x-4\Leftrightarrow-2x+5=3x-4\Leftrightarrow5x=9\Leftrightarrow x=\dfrac{9}{5}\)

e, \(x^2+4x+4+x^2-2x+1=2x^2-18\Leftrightarrow2x+5=-18\Leftrightarrow x=-\dfrac{23}{2}\)