cau 44 trang 92 toan lop 8(hinh)
giai dum mk nha
cho tam giac ABC.Goi M,N,P lan luot la trung diem AB,AC,BC.CM:tu giac BMNP la hinh binh hanh.
Ve hinh ,giai chi tiet.
tính :
A=\(\dfrac{x^2}{\left(x-y\right)^2.\left(x+y\right)}-\dfrac{2xy^2}{x^4-2x^2y^2+y^4}+\dfrac{7^2}{\left(x^2-y^2\right)\left(x+y\right)}\)
B=\(\dfrac{x+3}{x+1}-\dfrac{2x-1}{x-1}-\dfrac{x-3}{x-1}\)
thực hiện phép tính
a)\(\dfrac{2x^2-20x+50}{3x+3}\times\dfrac{x^2-1}{4\left(x-5\right)^2}\)
b) \(\dfrac{6x-3}{5x^2+x}\times\dfrac{25x^2+10x+1}{1-8x^3}\)
c) \(\dfrac{3x^2-x}{x^2-1}\times\dfrac{1-x^4}{\left(1-3x\right)^3}\)
Cho bt
P=\(\left(\dfrac{x-2}{x^2-1}-\dfrac{x+2}{x^2+2x+1}\right)\left(\dfrac{1-x^2}{2}\right)^2\)
a) rút gọn P
b) tìm x để \(\dfrac{P-4}{5}=x\)
Tính :
a)\(\left(2x^4-5x^3+2x^2+2x-1\right):\left(x^2-x-1\right)\)
b)\(\left(2x^3-5x^2+6x-15\right)\left(2x-5\right)\)
c)\(\left(x^4-2x^3+5x-6\right):\left(x-3\right)\)
thực hiện phép tính
a)\(\dfrac{4x+2}{3x^2-x}:\dfrac{x^2+3x}{1-3x}\)
b)\(\dfrac{4x+6y}{x-1}:\dfrac{4x^2-12xy+9y^2}{1-x^2}\)
c) \(\dfrac{x^4-xy^3}{2xy+y^2}:\dfrac{x^3+x^2y+xy^2}{2x+y}\)
thực hiện phép tính
a)\(\dfrac{x^3}{x^2+1975}\times\dfrac{2x+1954}{x+1}+\dfrac{x^3}{x^2+1975}\times\dfrac{21-x}{x+1}\)
b)\(\dfrac{19x+8}{x-7}\times\dfrac{5x-9}{x+1945}+\dfrac{19x+8}{x^2+1945}\times\dfrac{1x-2}{x-7}\)
c) \(\dfrac{x+1}{x^2-2x-8}\times\dfrac{4-x}{x^2+x}\)
sắp xếp
1 They / live / the city / for / 2 years
2 Vietnam students / have/ many / vacation / than / English ones ?
3 Our father / used / take / us / zoo / when we / young
4 she / live / this city / since / 2003
5 Tim/ want / improve his Spanish pronunciation