Question

Tìm x biết: 2x(5-3x)+2x(3x-5)-3(x-7)=3

Answer 1

2x(5-3x)+ 2x(3x-5)-3(x-7)=3

⇔\(10x-6x^2+6x^2-10x-3x+21=3\)

⇔\(-3x+21\)

⇔\(-3x=3-21\)

⇔\(-3x=-18\)

⇔\(x=6\)

Answer 2

Tìm x biết: 2x(5-3x)+2x(3x-5)-3(x-7)=3

=> \(10x-6x^2+6x^2-10x-3x+21=3\)

=> \(-13x+21=3=>-13x=-18x=>x=\frac{18}{13}\)