đáp án:

1+1=2

so ez

1 + 1 = 2

Hok tốt

(-5)+(-11)

\(\left(x-1\right)\left(x-4\right)\left(x-5\right)\left(x-8\right)+36=0\)

\(\left[\left(x-1\right)\left(x-8\right)\right]\left[\left(x-4\right)\left(x-5\right)\right]+36=0\)

\(\left(x^2-9x+8\right)\left(x^2-9x+20\right)+36=0\)

Đặt \(a=x^2-9x+14\)ta có :

\(\left(a-6\right)\left(a+6\right)+36=0\)

\(a^2-6^2+36=0\)

\(a^2=0\)

Thay \(a=x^2-9x+14\)ta có :

\(\left(x^2-9x+14\right)^2=0\)

\(\Leftrightarrow x^2-9x+14=0\)

\(\Leftrightarrow x^2-2x-7x+14=0\)

\(\Leftrightarrow x\left(x-2\right)-7\left(x-2\right)=0\)

\(\Leftrightarrow\left(x-2\right)\left(x-7\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x-2=0\\x-7=0\end{cases}\Rightarrow\orbr{\begin{cases}x=2\\x=7\end{cases}}}\)

Vậy,...........

dấu ngang ngang là phần nha

\(\frac{x+2}{x-2}-\frac{x-2}{x+2}+\frac{16}{4-x^2}\)

\(=\frac{\left(x+2\right)\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}-\frac{\left(x-2\right)\left(x-2\right)}{\left(x-2\right)\left(x+2\right)}+\frac{-16}{\left(x-2\right)\left(x+2\right)}\)

\(=\frac{\left(x+2\right)^2-\left(x-2\right)^2-16}{\left(x-2\right)\left(x+2\right)}\)

\(=\frac{x^2+4x+4-x^2+4x-4-16}{\left(x-2\right)\left(x+2\right)}\)

\(=\frac{8x-16}{\left(x-2\right)\left(x+2\right)}\)

\(=\frac{8\left(x-2\right)}{\left(x-2\right)\left(x+2\right)}\)

\(=\frac{8}{x+2}\)

bạn ơi, cho mình hỏi

4-x² thì sẽ = 2²-x² = (2-x)(2+x)

vậy sao bạn ghi là (x-2)(x+2) vậy???

violet đó bạn

VN cố lên

cố lên

cố lên

c...ố... lê..n

12 + 6 + 2018 = 2036

Việt Nam sẽ thắng!!! Việt Nam vô địch!!!

Mong VN sẽ tỏa sáng.