Tính
a)\(\left(x^4+2x^3+10x-25\right):\left(x^2+5\right)\)
b) \(\left(3x^4-8x^3-10x^2+8x-5\right):\left(3x^2-2x+1\right)\)
1, Tính
a) \(\dfrac{3x^2-5}{x^2-5x}+\dfrac{5-15x}{5x-25}\)
b) \(\dfrac{4+x^3}{x-3}-\dfrac{2x+2x^2}{x-3}+\dfrac{2x-13}{x-3}\)
c) \(\dfrac{2}{x-5}+\dfrac{x-25}{\left(x+5\right)\left(x-5\right)}\)
d) \(\dfrac{2x+8}{x^2-12+1}+\dfrac{7}{x-2}\)
2. Tính giá trị biểu thức
A= \(2\left(x+1\right)+\left(3x+2\right)\left(3x-2\right)-9x^2\)
tại \(x=15\)
a.\(\dfrac{x+6}{5}-\dfrac{x-2}{3}< 2\)
b. \(\dfrac{x+5}{4}-\dfrac{x^{2^{ }}-3}{6}\ge1-\dfrac{2x^{2^{ }}-1}{12}\)
c. \(x^{2^{ }}-4x+3>0\)
d. \(x^{3^{ }}-2x^{2^{ }}+3x-2\ge0\)
e. \(\left|x+1\right|+\left|x-2\right|=4\)
f. \(\dfrac{5x-1}{10}+\dfrac{2x+3}{6}>\dfrac{x-8}{15}-\dfrac{x-1}{30}\)
h.\(\dfrac{10x+3}{12}< \dfrac{15-8x}{9}\)
\(A=\left(\dfrac{x-5\sqrt{x}}{x-25}-1\right):\left(\dfrac{25-x}{x+2\sqrt{x}-15}-\dfrac{\sqrt{x}+3}{\sqrt{x}+5}+\dfrac{\sqrt{x}-5}{\sqrt{x}+3}\right)\)
\(B=\left(\dfrac{2+x}{2-x}-\dfrac{4x^2}{x^2-4}-\dfrac{2-x}{x+2}\right):\dfrac{x^2-3x}{2x^2-x^3}\)
a) Rút gọn A & B
b) Tìm x để B > 0
c) Tính B khi \(\left|1-x\right|=0\)
Thực hiện phép tính các đa thức sau
a) \(\left(3x^2-2x+5\right)\left(2x^2-3x+1\right)\)
b) \(\left(\dfrac{3}{2}x^2-\dfrac{2}{3}x-\dfrac{5}{3}\right)\left(4x^2-\dfrac{3}{2}x-3\right)\)
c) \(\left(\dfrac{3}{4}x^2+2x-\dfrac{1}{3}\right)\left(4x^2-\dfrac{3}{2}x-3\right)\)
d) \(\left(-\dfrac{1}{3}+2x-x^2\right)\left(-2x^2-\dfrac{1}{2}x+2\right)\)
e) \(\left(3xy+\dfrac{1}{2}x\right)\left(3x^{2y}-3xy^2-1\right)\)
Cho biểu thức:
B=\(\left(\dfrac{x^2}{x^2-4x}-\dfrac{10x}{5x-10}-\dfrac{1}{2-x}\right):\left(x+2+\dfrac{6-x^2}{x-2}\right)\)
a/ Rút gọn B
b/ Tính B biết \(\left|x\right|=\dfrac{1}{2}\)
c/ Tìm x biết B=-1
d/ Tìm x để B>0
e/ Tìm x nguyên để B nguyên
Tìm x biết :
a) \(\left(x-2\right)^3+6\left(x+1\right)^2-x^3+12=0\)
b) \(\left(x-5\right)\left(x+5\right)-\left(x+3\right)^3+3\left(x-2\right)^2=\left(x+1\right)^2-\left(x+4\right)\left(x-4\right)+3x^2\)
c) \(\left(2x+3\right)^2+\left(x-1\right)\left(x+1\right)=5\left(x+2\right)^2-\left(x-5\right)\left(x+1\right)+\left(x+4\right)^2\)
d) \(\left(1-3x\right)^2-\left(x-2\right)\left(9x+1\right)=\left(3x-4\right)\left(3x+4\right)-9\left(x+3\right)^2\)
Bài 1. tính giá trị biểu thức.
a. \(5x\left(4x^2-2x+1\right)-2x\left(10x^2-5x+2\right)\) với x = 15
b.\(5x\left(x-4y\right)-4y\left(y-5x\right)\) tại \(x=\dfrac{-1}{5}\) và \(y=\dfrac{-1}{2}\)
c.\(6xy\left(xy-y^2\right)-8x^2\left(x-y^2\right)+5y^2\left(x^2-xy\right)\)với \(x=\dfrac{1}{2};y=2\)
giúp mik với mik đang cần gấp cảm ơn
Mọi người ơi, giúp mình với mình đang cần gấp
thank mọi người
1 thực hiện phép nhân
1)\(-3\left(-x+3\right)\)
2)\(-5x^3\left(-3x+5\right)\)
3)\(-2x\left(-2x-6\right)\)
4)\(-3x^3\left(-2x-12\right)\)
5)\(-10x\left(-5x+2\right)\)
6)\(-2x^2\left(-3x^3+4x^2-5\right)\)
7)\(-x^2\left(-2x^3-x+3\right)\)
8)\(-2^3\left(-2-6\right)\)
9)\(\left(-x-3\right)\left(x+2\right)\)
10)\(\left(2x-3\right)\left(5-x\right)\)
11)\(\left(-x+6\right)\left(-x-2\right)\)
12)\(\left(3x-1\right)\left(-3-2x\right)\)
13)\(\left(-5x-3\right)\left(2-x\right)\)
14) \(\left(2x-1\right)\left(4x^2+2x+1\right)\)
15) \(\left(x-3\right)\left(1-2x-5y\right)\)
16)\(\left(x-2\right)\left(x^2+4\right)\left(x+2\right)\)
17)\(\left(-3+1\right)\left(9x^2+1\right)\left(-3x-1\right)\)
18)\(-\left(2x+1\right)\left(2-1\right)\left(x+1\right)\)
19)\(\left(2x^2-3x+5\right)\left(x^2-8x+2\right)\)
20)\(\left(3x^2y-6xy+9x\right)\left(-xy\right)\)