A= (4-5x)(3x-2) + (3-2x)(x-2)

A= 12x - 8 - 15x² + 10x + 3x - 6 - 2x² + 4x

A= (12x + 10x + 3x +4x) - (8 +6) -(15x² + 2x²)

A= 29x - 14 - 17x²

Vậy A= 29x - 14 - 17x²

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em chịu anh ơi, em lớp 6

em thì lớp 7 cũng chụi lung anh ơi

Giả sử góc A < góc D. Chứng minh AC > BD

Dựng tia AE sao cho: góc DAE = góc ADC để được hình thang cân ADCE.

Ta có: góc AEC = góc DCE và AC = DE

Ta có: góc EBD > góc DCB > góc DEB

=> ED > BD => AC > BD

 100000000000 chia hết cho chính nó , chia cho 5 , chia cho 2 , chia 10 , chia 100 vv

Dễ ẸC 

\(\text{100000000000}:\text{100000000000}=0\)

IQ 1000000000000000000000000000000000000000000000000000000000000 là tui ^^

\(x(x-5)(x+5)-(x+2)(x^2-2x+4)\)

\(\Leftrightarrow x(x^2-25)-(x^3+8)\)

\(\Leftrightarrow x^3-25x-x^3-8\)

\(\Leftrightarrow-25x=11\Leftrightarrow x=-\frac{11}{25}\)

\(x\left(x-5\right)\left(x+5\right)-\left(x+2\right)\left(x^2-2x+4\right)\)

\(\rightarrow\)\(x\left(x^2-25\right)-\left(x^3+8\right)\)

\(\rightarrow\)\(x^3-25x-x^3-8\)

\(\rightarrow\)\(-25x=11\Leftrightarrow x=-\frac{11}{25}\)