Question

Rút gọn:

\(C=2x\left(-3x+5\right)+3x\left(2x-12\right)+26x\)

\(D=\frac{-2x}{3}+3x\left(\frac{x}{6}-\frac{-2}{9}\right)-\frac{5x}{2}\left(\frac{x}{5}-\frac{4}{5}\right)\)

Giúp với nha, đây là bài HK2 lớp 7 nhưng có p nào bít làm thì giải giùm nha! Thứ 3 mình nộp bài. 

                                                    \(Thanks\)

Answer 1

\(C=2x\left(-3x+5\right)+3x\left(2x-12\right)+26x\)

\(=-6x^2+10x+6x^2-36x+26x\)

\(=-6x^2+6x^2+10x-36x+26=0\)

\(D=\frac{-2x}{3}+3x\left(\frac{x}{6}-\frac{-2}{9}\right)-\frac{5x}{2}\left(\frac{x}{5}-\frac{4}{5}\right)\)

\(=\frac{-2x}{3}+\frac{x^2}{2}+\frac{2x}{3}-\frac{x^2}{2}+2x\)

\(=-\frac{2x}{3}+\frac{2x}{3}+\frac{x^2}{2}-\frac{x^2}{2}+2x=2x\)

Answer 2

minh moi hoc lop 6 thui

Answer 3

Dễ thì làm đi Phạm Văn Khánh 

Answer 4

\(C=-6x^2+10x+6x^2-36x+26x=\left(-6x^2+6x^2\right)+\left(10x+26x-36x\right)=0+0=0\)

\(D=-\frac{2x}{3}+\frac{x^2}{2}+\frac{2x}{3}-\frac{x^2}{2}+2x=\left(-\frac{2x}{3}+\frac{2x}{3}\right)+\left(\frac{x^2}{2}-\frac{x^2}{2}\right)+2x=0+0+2x=2x\)

Answer 5

\(C=-6x^2+10x+6x^2-36x+26x=0x\)

\(D=\frac{-2x}{3}+\frac{3x^2}{6}+\frac{6x}{9}-\frac{5x^2}{10}+\frac{20x}{10}\)

      \(=\frac{-2x}{3}+\frac{x^2}{2}+\frac{2x}{3}-\frac{x^2}{2}+2x\)

      \(=2x\)