-3y2 hay là- -3y mũ 2 hay -3y tất cả mũ 2 thế ạ, vs lại bn đánh thiếu 1 cái dấu đóng ngoặc nha ,vị trí đánh ngoặc bn đánh thiếu đặt ở đâu á?

bn đánh đề chữ cho mik vs chứ đề số bn đánh khó hiểu quá

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

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

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

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

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

\(\frac{x+4}{x^2-4}-\frac{2}{x^2+2x}ĐK:x\ne\pm2;0\)

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

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

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

\(A=\left(\frac{\left(1-x\right)\left(1+x+x^2\right)}{1-x}-x\right):\frac{\left(1-x^2\right)}{\left(1-x^2\right)\left(1-x\right)}\)

\(\Leftrightarrow A=\left(1+x+x^2-x\right):\frac{1}{1-x}=\left(1+x^2\right)\left(1-x\right)\)

\(8^5+2^{11}=\left(2^3\right)^5+2^{11}=2^{15}+2^{11}=2^{11}\left(2^4+1\right)=2^{11}.17⋮17\)

bài làm