a) \(x\left(5-2x\right)-2x\left(1-x\right)=15\\ \Leftrightarrow5x-2x^2-2x+2x^2=15\\ \Leftrightarrow3x=15\\ \Leftrightarrow x=5\)
Vậy x = 5 là nghiệm của pt.
b) \(\left(3x+2\right)^2+\left(1+3x\right)\left(1-3x\right)=2\\ \Leftrightarrow\left(9x^2+12x+4\right)+1-9x^2=2\\ \Leftrightarrow12x+5=2\\ \Leftrightarrow12x=-3\\ \Leftrightarrow x=\dfrac{-1}{4}\)
Vậy \(x=-\dfrac{1}{4}\) là nghiệm của pt.
a)x.(5-2x)-2x.(1-x)=15
x [ 5 - 2x -2.(1-x) ] = 15
x ( 5 - 2x -2 + 2x ) =15
x . 3 =15
x = 5
b)(3x+2)2+(1+3x).(1-3x)=2
9x2+12x+4+1-9x2=2
12x + 5 = 2
12x = -3
x = -1/4
Tìm x:
\(x\left(5-2x\right)-2x\left(1-x\right)=15\)
\(\Leftrightarrow5x-2x^2-2x+2x^2=15\)
\(\Leftrightarrow3x=15\\ \Leftrightarrow x=5\)
\(\left(3x+2\right)^2+\left(1+3x\right)\left(1-3x\right)=2\)
\(\Leftrightarrow9x^2+12x+4+1-9x^2=2\)
\(\Leftrightarrow12x=-3\\ \Leftrightarrow x=\dfrac{-1}{4}\)
