Question

[Không Tồn Tại]

Tìm x: 

a) 4x( x - 5) - ( x - 1)( 4x - 3) = 5

b) ( 12x - 5)( 4x - 1) + ( 3x - 7)( 1 - 16x) = 81

c) ( x - 1)( 2x - 3) - ( x + 3)( 2x - 5) = 4

Mk gấp lắm, ai nhanh mk tick nha!

Answer 1

[Trịnh Thành Công]

a)\(4x\left(x-5\right)-\left(x-1\right)\left(4x-3\right)=5\)

    \(4x^2-20x-\left(4x^2-7x+3\right)=5\)

    \(4x^2-20x-4x^2+7x-3=5\)

     \(-13x=8\)

      \(x=-\frac{8}{13}\)

b)\(\left(12x-5\right)\left(4x-1\right)+\left(3x-7\right)\left(1-16x\right)=81\)

     \(48x^2-32x+5+3x-48x^2-7+112x=81\)

     \(83x-2=81\)

     \(x=1\)