B=\(\frac{5\left(x-y\right)-3\left(x-y\right)}{10\left(x-y\right)}\)
B=\(\frac{\left(x-y\right)\left(5-3\right)}{10\left(x-y\right)}\)
B= \(\frac{\left(x-y\right)2}{10\left(x-y\right)}\)
B= 5
vậy B=5
Rút gọn \(\frac{1}{\left(x+y\right)^3}.\left(\frac{1}{x^3}+\frac{1}{y^3}\right)+\frac{3}{\left(x+y\right)^5}.\left(\frac{1}{x^2}+\frac{1}{y^2}\right)+\frac{6}{\left(x+y\right)^5}.\left(\frac{1}{x}+\frac{1}{y}\right)\)
rút gọn
a) \(\frac{1}{x-y}-\frac{3xy}{x^2-y^2}+\frac{x-y}{x^2+x+y^2}\)
b) \(\frac{1}{x^2+3x+2}+\frac{1}{x^2+4x+4}+\frac{1}{x^2+5x+6}\)
c) \(\frac{4.\left(x+3\right)^2}{\left(3x+5\right)^2-4x^2}-\frac{x^2-25}{9x^2.\left(2x+5\right)^2}-\frac{\left(2x+3\right)^2-x^2}{\left(4x+15\right)^2-x^2}\)
Cộng trừ phân số
1)\(x+2+\frac{3}{x-2}\)
2)\(\frac{x^2}{\left(x-y\right)\left(x-z\right)}+\frac{y^2}{\left(y-x\right)\left(y-z\right)}+\frac{z^2}{\left(z-x\right)\left(z-y\right)}\)
\(P=\frac{x^2}{\left(x+y\right)\left(x-y\right)}-\frac{y}{\left(x+y\right)\left(x+1\right)}-\frac{x^2y^2}{\left(x+1\right)\left(1-y\right)}.\)
Tìm các cặp số x,y thuộc Z để P = 3.
Cho \(\frac{x}{a}=\frac{y}{b}=\frac{z}{c}\ne0\). Rút gọn biểu thức \(\frac{\left(x^2+y^2+z^2\right)\left(a^2+b^2+c^2\right)}{\left(ax+by+cz\right)^2}\)
Câu 1: Cho \(\frac{x}{x^2+x+1}\)=\(\frac{11}{133}\)
Tính A=\(\frac{x^2}{x^4+x^2+1}\)( 2 cách)
Câu 2: Cho x+y+z=4. Tính B=\(\frac{x^3+y^3+z^3-3xyz}{\left(x-y\right)^2+\left(y-z\right)^2+\left(z-x\right)^2}\)
Câu 3: Cho G=\(\frac{a^2}{ab+b^2}+\frac{b^2}{ab-a^2}+\frac{-\left(a^2+b^2\right)}{ab}\)
a) Rút gọn G
b) Tính G khi \(\frac{a}{b}=\frac{a+1}{b+5}\)
c/m các biểu thức sau không phụ thuộc vào biến x,y
a) \(\frac{\left(x+a\right)^2-x^2}{2x+a}\)
b) \(\frac{x^2-y^2}{axy-ax^2-ay^2-axy}\)
c) \(\frac{2ax-2x-3y+3ay}{4ax+6y+9y+6ay}\)
Rút gọn biểu thức sau:
\(A=\frac{x^2-yz}{\left(x+y\right)\left(y+z\right)}+\frac{y^2-xz}{\left(x+y\right)\left(y+z\right)}+\frac{z^2-xy}{\left(x+z\right)\left(y+z\right)}\)
Cộng trừ phân số
\(\frac{x^2}{\left(x-y\right)^2\left(x+y\right)}-\frac{2xy^2}{x^4-2x^2y^2+y^4}+\frac{y^2}{\left(x^2-y^2\right)\left(x+y\right)}\)
