=>(1+2+3+......+2016).x=4070306

=>2033136.x=4070306

=>x=4070306:2033136

=>x=\(\frac{1009}{504}\)

=> (x + x + x + .... + x) . (1 + 2 + 3 + ..... + 2016) = 2017.2018

=> 2016x . 1008 . 2017 = 2017 . 2018

=> 2016x . 1008 = 2018

=> /////////////

Cậu viết sai đề bài rồi!!!

1) \(x+2\cdot x+3\cdot x+4\cdot x+...+2016\cdot x=2016\cdot2017\)

\(=x\cdot\left(2+3+4+...+2016\right)=4066272\)

\(=x\cdot2033136=4066272\)

\(\Rightarrow x=\frac{4066272}{2033136}=2\)

2) \(x-2\cdot x+3\cdot x-4\cdot x+...-2016\cdot x=2016\cdot2017\)

\(x\cdot\left\{\left(-2+\left(-4\right)+\left(-6\right)+...+\left(-2016\right)\right)+\left(1+3+5+7+...+2015\right)\right\}=4066272\)

\(x\cdot\left\{\left(-1017072\right)+1016064\right\}=4066272\)

\(x\cdot\left(-1008\right)=4066272\)

\(\Rightarrow x=-\frac{4066272}{1008}=-4034\)

x(1+2+3...2016)=2017.2018

 x.2017.2016:2=2017.2018

 1008x=2018

 x=1009/504

x+2x+3x+......+2016x=2017.2018

\(\Rightarrow\)x.(1+2+3+....+2016)=2017.2018

\(\Rightarrow\)x.2033136=2017.2018

\(\Rightarrow\)x=(2017.2018):2033136

x=\(\dfrac{1009}{504}\)

Chúc bạn học tốt!

1) \(\Rightarrow10x-16-12x+15=12x-16+11\)

\(\Rightarrow14x=4\Rightarrow x=\dfrac{2}{7}\)

2) \(\Rightarrow4x^2+4x+1-4x^2+13x-3-15=0\)

\(\Rightarrow17x=17\Rightarrow x=1\)

3) \(\Rightarrow\left(3x-1\right)\left(2x-7+6x-5\right)=0\)

\(\Rightarrow\left(2x-3\right)\left(3x-1\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=\dfrac{1}{3}\end{matrix}\right.\)

2: Ta có: \(\left(2x+1\right)^2-\left(4x-1\right)\left(x-3\right)-15=0\)

\(\Leftrightarrow4x^2+4x+1-4x^2+12x+x-3-15=0\)

\(\Leftrightarrow17x=17\)

hay x=1