a) 3x (12x - 4) - 9x (4x - 3) = 30;
b) x (5 - 2x) + 2x (x - 1) = 15.
tìm x,biết: a,3x(12x-4)-9x(4x-3)=30
3x.(12x-4)-9x.(4x-3)=30
3x.(12x-4)-9x.(4x-3)=30
=> 36x2-12x-36x2+27x=30
=> 15x=30
=> x=30:15
=> x=2
3x.(12x-4)-9x(4x-3)=30
3x(12x-4)-9x(4x-3)=30
<=>36x2-12x-36x2+27x=30
<=>15x=30
<=>x=2
3x.(12x-4)-9x.(4x-3)=30
\(3x.\left(12x-4\right)-9x.\left(4x-3\right)=30\)
\(36x^2-12x-36x^2=27x=30\)
\(15x=30\)
\(x=2\)
\(3x\left(12x-4\right)-9x\left(4x-3\right)=30\)
\(\Rightarrow36x^2-12x-36x^2+27x=30\)
\(\Rightarrow\left(36x^2-36x^2\right)+\left(27x-12x\right)=30\)
\(\Rightarrow15x=30\)
\(\Rightarrow x=2\)
\(3x\left(12x-4\right)-9x\left(4x-3\right)=30\)
\(\Rightarrow36x^2-12x-36x^2+27x=30\)
\(\Rightarrow15x=30\Rightarrow x=2\)
Vậy...............
Chúc bạn học tốt!!!
3x(12x-4)-9x(4x-3)=30
\(\Rightarrow36x^2-12x-36x^2+27x=30\)
\(\Rightarrow15x=30\Rightarrow x=30:15=2\)
Tìm x, biết: 3x(12x – 4) – 9x(4x – 3) = 30
3x(12x – 4) – 9x(4x – 3) = 30
3x.12x – 3x.4 – (9x.4x – 9x.3) = 30
36x2 – 12x – 36x2 + 27x = 30
(36x2 – 36x2) + (27x – 12x) = 30
15x = 30
x = 2
Vậy x = 2.
Tìm X a) 3x . ( 12x-4) - 9x . (4x-3)= 30 b) 6 . ( 2x+1) - 5 . ( X-2) = 10
a) \(3x\cdot\left(12x-4\right)-9x\cdot\left(4x-3\right)=30\)
\(\Leftrightarrow36x^2-12x-36x^2+27x=30\)
\(\Leftrightarrow15x=30\)
\(\Leftrightarrow x=\dfrac{30}{15}\)
\(\Leftrightarrow x=2\)
b) \(\left(2x+1\right)-5\left(x-2\right)=10\)
\(\Leftrightarrow2x+1-5x+10=10\)
\(\Leftrightarrow-3x+11=10\)
\(\Leftrightarrow-3x=10-11\)
\(\Leftrightarrow-3x=-1\)
\(\Leftrightarrow x=\dfrac{1}{3}\)
3x (12x -4 )- 9x (4x-3)= 30 . tìm x
3x (12x -4 )- 9x (4x-3)= 30
<=>36x2-12x-36x3+27x=30
<=>15x=30
<=>x=2
Tìm x :
3x(12x - 4) - 9x(4x - 3) = 30
\(3x\left(12x-4\right)-9x\left(4x-3\right)=30\)
\(36x^2-12x-36x^2+27x=30\)
\(15x=30\)
\(x=\frac{30}{15}\)
\(x=2\)
3X(12X-4) - 9X(4X-3)=30
Tìm X ?
= 36X-12X-36X-27X=30
=36X-36X-12X-27X=30
=0-12X-27X
=-12X-27X=30
=X.(-12-27)=30
hình như mình tính sai
nếu công thức đúng thì k nha
\(3x\left(12x-4\right)-9x\left(4x-3\right)=30\)
\(\Leftrightarrow15x=30\)
\(\Leftrightarrow x=2\)
3x(12x+4)-9x(4x-3)=30
=>36.x2+12x-36.x2-27x=30
=>12x-27x=30
=>-15x=30
=>x=30:(-15)
=>x=-2
vậy......