Rút gọn biểu thức:
a, \(\frac{x^4+15x+7}{2x^3+2}.\frac{x}{14x^2+1}.\frac{4x^3+4}{x^4+15x+7}\)
b, \(\frac{x^7+3x^2+2}{x^3-1}.\frac{3x}{x+1}.\frac{x^2+x+1}{x^7+3x^2+2}\)
Rút gọn biểu thức :
a) \(\dfrac{x^4+15x+7}{2x^3+2}.\dfrac{x}{14x^2+1}.\dfrac{4x^3+4}{x^4+15x+7}\)
b) \(\dfrac{x^7+3x^2+2}{x^3-1}.\dfrac{3x}{x+1}.\dfrac{x^2+x+1}{x^7+3x^2+2}\)
a: \(=\dfrac{x^4+15x+7}{x^4+15x+7}\cdot\dfrac{x}{14x^2+1}\cdot\dfrac{4x^3+4}{2x^3+2}=\dfrac{2x}{14x^2+1}\)
b: \(=\dfrac{x^7+3x^2+2}{x^7+3x^2+2}\cdot\dfrac{x^2+x+1}{x^3-1}\cdot\dfrac{3x}{x+1}\)
\(=\dfrac{1}{x-1}\cdot\dfrac{3x}{x+1}=\dfrac{3x}{x^2-1}\)
tính ;
\(\frac{x^4+15x+7}{2x^3}-\frac{x}{14x^2}x\frac{4x^3}{x^4+15x+7}\)
Giải phương trình sau
\(\frac{2x-1}{3x^2+7\:x+2}+\frac{3}{9x^2+15x+4}-\frac{2x+7}{3x^2-5x-12}=\frac{5}{x+2}\)
\(\frac{2x-1}{3x^2+7x+2}+\frac{3}{9x^2+15x+4}-\frac{2x+7}{3x^2-5x-12}=\frac{5}{x+2}\)
\(\Leftrightarrow\frac{2x-1}{\left(3x+1\right)\left(x+2\right)}+\frac{3}{\left(3x+1\right)\left(3x+4\right)}-\frac{2x+7}{\left(4x+3\right)\left(x-3\right)}=\frac{5}{\left(x+2\right)}\)
\(\Leftrightarrow\frac{1}{x+2}-\frac{1}{3x+1}+\frac{1}{3x+1}-\frac{1}{3x+4}+\frac{1}{3x+4}-\frac{1}{x-3}=\frac{5}{x+2}\)
\(\Leftrightarrow\frac{1}{x+2}-\frac{1}{x-3}=\frac{5}{x+2}\)
\(\Leftrightarrow\frac{x-3-x-2}{\left(x+2\right)\left(x-3\right)}=\frac{5\left(x-3\right)}{\left(x+2\right)\left(x-3\right)}\)
\(\Leftrightarrow5x-3=-5\)
\(\Leftrightarrow x=-\frac{2}{5}\)
Chúc bạn học tốt !!!
Rút gọn biểu thức sau: A=\(\left[\left(x^4-x+\frac{x-3}{x^3+1}\right).\frac{\left(x^3-2x^2+2x-1\right)\left(x+1\right)}{x^9+x^7-3x^2-3}+1-\frac{2\left(x+6\right)}{x^2+1}\right].\frac{4x^2+4x+1}{\left(x+4\right)\left(3-x\right)}\)
giải các hệ BPT sau:
a) \(\left\{{}\begin{matrix}5x-2>4x+5\\5x-4< x+2\end{matrix}\right.\)
b) \(\left\{{}\begin{matrix}2x+1>3x+4\\5x+3\ge8x-9\end{matrix}\right.\)
c) \(\left\{{}\begin{matrix}\frac{5x+2}{3}\ge4-x\\\frac{6-5x}{13}< 3x+1\end{matrix}\right.\)
d) \(\left\{{}\begin{matrix}\frac{4x-5}{7}< x+3\\\frac{3x+8}{4}>2x-5\end{matrix}\right.\)
e) \(\left\{{}\begin{matrix}6x+\frac{5}{7}< 4x+7\\\frac{8x+3}{2}< 2x+5\end{matrix}\right.\)
f) \(\left\{{}\begin{matrix}15x-2>2x+\frac{1}{3}\\2\left(x-4\right)< \frac{3x-14}{2}\end{matrix}\right.\)
g) \(\left\{{}\begin{matrix}x-1\le2x-3\\3x< x+5\\5-3x\le2x-6\end{matrix}\right.\)
h) \(\left\{{}\begin{matrix}2x+\frac{3}{5}>\frac{3\left(2x-7\right)}{3}\\x-\frac{1}{2}< \frac{5\left(3x-1\right)}{2}\end{matrix}\right.\)
j) \(\left\{{}\begin{matrix}\frac{3x+1}{2}-\frac{3-x}{3}\le\frac{x+1}{4}-\frac{2x-1}{3}\\3-\frac{2x+1}{5}>x+\frac{4}{3}\end{matrix}\right.\)
Bài 1: Thực hiện phép tính
a. \(\frac{11x+10}{3x-3}+\frac{15x+13}{4-4x}\)
b. \(\frac{5x+3}{x^2-3x}+\frac{9-x}{9-3x}\)
c. \(\frac{4xy-1}{5x^2y}-\frac{2xy-1}{5x^2y}\)
d. \(\frac{x+8}{x^2-16}-\frac{2}{x^2+4x}\)
e. \(\frac{x^2-49}{2x+1}.\frac{3}{7-x}\)
f. \(\frac{3x^2-2x}{x^2-1}.\frac{1-x^4}{\left(2-3x\right)^3}\)
g. \(\frac{5xy}{2x-3}:\frac{15xy^3}{12-8x}\)
h. \(\frac{x^2+2x}{3x^2-6x+3}:\frac{2x+4}{5x-5}\)
Các ĐKXĐ: bạn tự tìm
a)
\(\frac{11x+10}{3x-3}+\frac{15x+13}{4-4x}=\frac{11x+10}{3(x-1)}-\frac{15x+13}{4(x-1)}=\frac{4(11x+10)-3(15x+13)}{12(x-1)}\)
\(=\frac{-x+1}{12(x-1)}=\frac{-(x-1)}{12(x-1)}=\frac{-1}{12}\)
b)
\(\frac{5x+3}{x^2-3x}+\frac{9-x}{9-3x}=\frac{5x+3}{x(x-3)}+\frac{x-9}{3x-9}=\frac{5x+3}{x(x-3)}+\frac{x-9}{3(x-3)}\)
\(=\frac{3(5x+3)}{3x(x-3)}+\frac{x(x-9)}{3x(x-3)}=\frac{x^2+6x+9}{3x(x-3)}=\frac{(x+3)^2}{3x(x-3)}\)
c)
\(\frac{4xy-1}{5x^2y}-\frac{2xy-1}{5x^2y}=\frac{(4xy-1)-(2xy-1)}{5x^2y}=\frac{2xy}{5x^2y}=\frac{2}{5x}\)
d)
$\frac{x+8}{x^2-16}-\frac{2}{x^2+4x}=\frac{x+8}{(x-4)(x+4)}-\frac{2}{x(x+4)}$
$=\frac{x(x+8)}{x(x-4)(x+4)}-\frac{2(x-4)}{x(x+4)(x-4)}$
$=\frac{x^2+8x-2(x-4)}{x(x+4)(x-4)}=\frac{x^2+6x+8}{x(x+4)(x-4)}$
$=\frac{(x+2)(x+4)}{x(x+4)(x-4)}=\frac{x+2}{x(x-4)}$
e)
$\frac{x^2-49}{2x+1}.\frac{3}{7-x}=\frac{(x-7)(x+7)}{2x+1}.\frac{-3}{x-7}$
$=\frac{-3(x+7)}{2x+1}$
f)
$\frac{3x^2-2x}{x^2-1}.\frac{1-x^4}{(2-3x)^3}$
$=\frac{2x-3x^2}{x^2-1}.\frac{x^4-1}{(2-3x)^3}=\frac{x(2-3x)(x^2-1)(x^2+1)}{(x^2-1)(2-3x)^3}$
$=\frac{x(x^2+1)}{(2-3x)^2}$
g)
$\frac{5xy}{2x-3}:\frac{15xy^3}{12-8x}=\frac{5xy}{2x-3}.\frac{12-8x}{15xy^3}$
$=\frac{5xy}{2x-3}.\frac{-4(2x-3)}{15xy^3}=\frac{-4}{3y^2}$
h)
$\frac{x^2+2x}{3x^2-6x+3}:\frac{2x+4}{5x-5}=\frac{x(x+2)}{3(x-1)^2}:\frac{2(x+2)}{5(x-1)}$
$=\frac{x(x+2)}{3(x-1)^2}.\frac{5(x-1)}{2(x+2)}$
$=\frac{5x}{6(x-1)}$
Bài 1: Thực hiện các phép tính sau
a.\(\frac{11x+10}{3x-3}+\frac{15x+13}{4-4x}\)
b.\(\frac{5x+3}{x^2-3x}+\frac{9-x}{9-3x}\)
c.\(\frac{4xy-1}{5x^2y}-\frac{2xy-1}{5x^2y}\)
d.\(\frac{x+8}{x^2-16}-\frac{2}{x^2+4x}\)
e.\(\frac{x^2-49}{2x+1}.\frac{3}{7-x}\)
f.\(\frac{3x^2-2x}{x^2-1}.\frac{1-x^4}{\left(2-3x\right)^3}\)
g.\(\frac{5xy}{2x-3}:\frac{15xy^3}{12-8x}\)
h.\(\frac{x^2+2x}{3x^2-6x+3}:\frac{2x+4}{5x-5}\)
Rút gọn \(B=\left(x^4-x+\frac{x-3}{x^3+1}\times\frac{\left(x^3-2x^2+2x-1\right)\left(x+1\right)}{x^9+x^7-3x^2-3}+1-\frac{2\left(x+6\right)}{x^2+1}\right)\times\frac{4x^2+6x+1}{\left(x+3\right)\left(4-x\right)}\)
1)2x(25x-4)-(5x-2)(5x+1)=8 / 5)\(2\left(x-2\right)-3\left(3x-1\right)=\left(x-3\right)\)
2)x(4x-3)-(2x-2)(2x-1)=5 / 6)\(\frac{2}{x+1}-\frac{1}{x-2}=\frac{3x-11}{\left(x+1\right)\left(x-2\right)}\)
3)\(\frac{5}{2x+3}+\frac{3}{9-x^2}=\frac{8}{7\left(x=3\right)}\) / 7)\(\frac{5x-2}{6}+\frac{3-4x}{2}=2-\frac{x+7}{3}\)
4)\(\frac{2}{3\left(x-2\right)}+\frac{5}{12-3x^2}=\frac{3}{4\left(x+2\right)}\) / 8)\(\frac{2}{x+1}-\frac{1}{x-2}=\frac{3x-11}{\left(x+1\right)\left(x-2\right)}\)
Đây là lớp 8 nha các b giúp mk với
Do mk viết nhầm