\(a\)) \(3x\left(12x-4\right)-9x\left(4x-3\right)=30\)
\(\Leftrightarrow3x\left(12x-4\right)-3x\left(12x-9\right)=30\)
\(\Leftrightarrow3x\left(12x-4-12x+9\right)=30\)
\(\Leftrightarrow3x.5=30\Leftrightarrow15x=30\)
\(\Leftrightarrow x=2\)
Vậy \(x=2\)
\(b\)) \(x\left(5-2x\right)+2x\left(x-1\right)=15\)
\(\Leftrightarrow x\left(5-2x\right)+x\left(2x-2\right)=15\)
\(\Leftrightarrow x\left(5-2x+2x-2\right)=15\)
\(\Leftrightarrow3x=15\Leftrightarrow x=5\)
Vậy \(x=5\)
a) 3x(12x-4)-9x(4x-3)=30
<=> 36x2-12x-36x2-27x=30
<=> -12x-(-27x) =30
<=> 15x =30
<=> x = 2
b) x(5-2x)+2x(x-1)=15
<=> 5x -2x2+2x2-2x=15
<=> 5x-2x =15
<=> 3x =15
<=> x =5
a,3x.(12x - 4) - 9x.(4x - 3) = 30
36x^2-12x-36x^2+27x =30
15x=30
x=2
b.x(5-2x)+2x(x-1)=15
=> 5x - 2x^2 + 2x^2 - 2x = 15
=> 3x = 15
=> x= 15 : 3
=> x = 5