a) 4x^2(5x^3 - 2x + 3)

= 20x^5 - 8x^3 + 12x^2

b) 2u(1 + u - v) - v(1 - 2u + v)

= 2u + 2u^2 - v - v^2

\(2u\left(1+u-v\right)-v\left(1-2y+v\right)\)

\(=2u+2u^2-2uv-u+2uv-v^2\)

\(=u+2y^2-v^2\)

a, \(x^2+2x\left(y+1\right)+y^2+2y+1=\left(x^2+2xy+y^2\right)+\left(2x+2y\right)+1\)

\(=\left(x+y\right)^2+2\left(x+y\right)+1=\left(x+y+1\right)^2\)

b, \(u^2+v^2+2u+2v+2\left(u+1\right)\left(v+1\right)+2\)

\(=u^2+v^2+2u+2v+2uv+2u+2v+2+2\)

\(=\left(u^2+2uv+v^2\right)+\left(4u+4v\right)+4\)

\(=\left(u+v\right)^2+4\left(u+v\right)+2^2=\left(u+v+2\right)^2\)

1.

a) \(A=x^2+2x\left(y+1\right)+y^2+2y+1\)

\(A=x^2+2x\left(y+1\right)+\left(y+1\right)^2\)

\(A=\left(x+y+1\right)^2\)

b) \(B=u^2+v^2+2u+2v+2\left(u+1\right)\left(v+1\right)+2\)\(B=u^2+v^2+2u+2v+2\left(u+1\right)\left(v+1\right)+1+1\)\(B=\left(u^2+2u+1\right)+2\left(u+1\right)\left(v+1\right)+\left(v^2+2v+1\right)\)\(B=\left(u+1\right)^2+2\left(u+1\right)\left(v+1\right)+\left(v+1\right)^2\)\(B=\left(u+1+v+1\right)^2=\left(u+v+2\right)^2\)

tik mik nha !!!

vecto a=-2*vecto u+vecto v

=>xa=-2*2+3=-1 và ya=-2*3+(-2)=-8

a.) \(A=x^2+y^2+1+2xy+2x+2y=\left(x+y+1\right)^2.\)

b.) \(B=u^2+v^2+2u+2v+2\left(u+1\right)\left(v+1\right)+2=u^2+2u+1+2\left(u+1\right)\left(v+1\right)+v^2+2v+1\)

\(B=\left(u+1\right)^2+2\left(u+1\right)\left(v+1\right)+\left(v+1\right)^2=\left(u+1+v+1\right)^2=\left(u+v+2\right)^2\)

Giả sử số tự nhiên a chia cho 7 dư 3. CMR a chia cho 7 dư 2

dùm mink câu này vs

\(B=\dfrac{2u+\sqrt{uv}-3v}{2u-5\sqrt{uv}+3v}\)

\(=\dfrac{2u+3\sqrt{uv}-2\sqrt{uv}-3v}{2u-2\sqrt{uv}-3\sqrt{uv}+3v}\)

\(=\dfrac{\sqrt{u}.\left(2\sqrt{u}+3\sqrt{v}\right)-\sqrt{v}.\left(2\sqrt{u}+3\sqrt{v}\right)}{2\sqrt{u}.\left(\sqrt{u}-\sqrt{v}\right)-3\sqrt{v}.\left(\sqrt{u}-\sqrt{v}\right)}\)

\(=\dfrac{\left(2\sqrt{u}+3\sqrt{v}\right)\left(\sqrt{u}-\sqrt{v}\right)}{\left(\sqrt{u}-\sqrt{v}\right)\left(2\sqrt{u}-3\sqrt{v}\right)}\)

\(=\dfrac{2\sqrt{u}+3\sqrt{v}}{2\sqrt{u}-3\sqrt{v}}\\ =\dfrac{4u+12\sqrt{uv}+9v}{4u-9v}\)

lô

xem lại đề bạn ơi. nếu( u+2v+1)+(2u-2v+2)=3u+3 và chưa chắc cái này đã lẻ

đề đúng mà

bn  tự thay t và s mà đề cho vào rồi tính bình thường 

còn câu cuối tương tự

Còn rút gọn cơ mà

tự rút gọn đi bạn

a) Rút gọn I = s 3   +   t 3  Þ I = 0.

b) Rút gọn N = u 3   – v 3  Þ N = 0.