Question

Tìm x biết:4(18-5x)-12(3x-7)-15(2x-16)-6(x+14)=0

Answer 1

\(4\left(18-5x\right)-12\left(3x-7\right)-15\left(2x-16\right)-6\left(x+14\right)=0\\ \Leftrightarrow72-20x-36x+84-30x+240-6x-84=0\\ \Leftrightarrow\left(-20x-36x-30x-6x\right)+\left(72+84+240-84\right)=0\\ \Leftrightarrow-92x+312=0\\\Leftrightarrow-92x=-312\\ \Leftrightarrow x=\frac{-312}{-92}=\frac{78}{23} \)

Vậy pt có tập nghiệm \(S=\left\{\frac{78}{23}\right\}\)

Answer 2

4(18 - 5x) - 12(3x - 7) - 15(2x - 16) - 6(x + 14) = 0

<=> 72 - 20x - 36x + 84 - 30x + 240 - 6x - 84 = 0

<=> 312 - 92x = 0

<=> 92x = 312

<=> x = \(\frac{78}{23}\)

Vậy x = \(\frac{78}{23}\)