1/x^2+x-2-x/x+1
e)x/2a-b-4ax/4a^2-b^2+b/2a+b
Quy đồng mẫu các phân thức sau:(có thể tính luôn càng tốt ạ)
a) \(\dfrac{a+x}{a^2x}\);\(\dfrac{x+b}{x^2b}\);\(\dfrac{b+a}{b^2a}\)
b) \(\dfrac{a-x}{6x^2-ax-2a^2}\);\(\dfrac{a+x}{3x^2+4ax-4a^2}\)
c) \(\dfrac{1-2x}{2x}\) + \(\dfrac{2x}{2x-1}\) + \(\dfrac{1}{2x-4x^2}\)
Mn giúp mik vs nhaaa! Tầm trc cmai nhoaaa!
Thanks mn trc ạ!!!
rút gọn biểu thức:
A=(x +2)(x-4)+(x+1)(x-6)
B=(2a - b)(4a^2 + 2ab + b^2)
C=(2 + x)(2 - x)(x + 4)
a: Ta có: \(A=\left(x+2\right)\left(x-4\right)+\left(x+1\right)\left(x-6\right)\)
\(=x^2-4x+2x-8+x^2-6x+x-6\)
\(=2x^2-7x-14\)
b: \(B=\left(2a-b\right)\left(4a^2+2ab+b^2\right)=8a^3-b^3\)
c: \(C=\left(2+x\right)\left(2-x\right)\left(x+4\right)\)
\(=\left(4-x^2\right)\left(x+4\right)\)
\(=4x+16-x^3-4x^2\)
Rút gọn :
A,\(\dfrac{2ax^2-4ax+2a}{5b-5b^2}\)
B,\(\dfrac{(x+y)^2-z^2}{x+y+z}\)
\(A=\dfrac{2a\left(x^2-2x+1\right)}{5b\left(1-b\right)}=\dfrac{2a\left(x-1\right)^2}{5b\left(1-b\right)}\)
\(B=\dfrac{\left(x+y+z\right)\left(x+y-z\right)}{x+y+z}=x+y-z\)
Rút gon: [16a^2-(4a-5)^2]^2-[9a^2-(3a 5)^2]^2
(x-3)^3-(x 3)^3 (1/2a b)^3 (1/2a-b)^3 (x 5)^3-x^3-125 (x-2)(x 2)(x 3)-(x 1)^3 (x 2)^3-(x-2)^3-12x^2C/m rằng
a) (a+3) .( a^2 -3a+9) - (54+x^3)
b) (2a+b) . (4a^2 -2ab +b^2 ) - (2a-b) . (4a^2+ +2ab +b^2)
c) (x +y)^2 - (x-y)^2
d) (x+y)^3 -( x-y)^3 -2y^3
Rút gọn:
\(a,\dfrac{2ax^2-4ax+2a}{5b-5bx^2}\)
\(b,\dfrac{\left(x+y^2\right)-z^2}{x+y+z}\)
\(a,\dfrac{2ax^2-4ax+2a}{5b-5bx^2}\)
\(=\dfrac{2a\left(x^2-2x+1\right)}{5b\left(1-x^2\right)}\)
\(=\dfrac{2a\left(x-1^2\right)}{5b\left(x-1\right)\left(1+x\right)}\)
\(=\dfrac{2a\left(x-1\right)}{5b\left(x+1\right)}\)
\(b,\dfrac{\left(x+y\right)^2-z^2}{x+y+z}\)
\(=\dfrac{\left(x+y-z\right)\left(x+y+z\right)}{x+y+z}=x+y-z\)
Rút gọn
a) A=3(x+1)^2/x^3-1 - 1-x/x^2+x+1 + 3/1-x
b) B= 2a/a^2-3a + a/a-1 + 2a/a^2-4a+3
Giải zùm mk vs
Quy đồng mẫu phân thức sau :
1.\(\frac{a-x}{6x^2-ax-2a^2};\frac{a+x}{3x^2+4ax-4a^2}\)
Giải phương trình:
a, \(\dfrac{t}{2a}-\dfrac{4a}{3}=1\)
b, \(\dfrac{x-2a}{b}=2+\dfrac{x+b}{a}\) (a, b là các hằng số)
a)A=\(\dfrac{1}{2a-1}\sqrt{5a^2\left(1-4a+4a^2\right)}\) với a>\(\dfrac{1}{2}\)
b)A=\(\dfrac{\sqrt{x-2\sqrt{x-1}}}{\sqrt{x-1}-1}\)+\(\dfrac{\sqrt{x+2\sqrt{x-1}}}{\sqrt{x-1+1}}\) với x>2
c)\(\dfrac{a+b}{b^2}\)\(\sqrt{\dfrac{a^2b^4}{a^2+2ab+b^2}}\) với a+b>0; b≠0
d)A=\(\left(\sqrt{\dfrac{1-a\sqrt{a}}{1-\sqrt{a}}}+\sqrt{a}\right)\left(\dfrac{1-\sqrt{a}}{1-a}\right)^2\) với a≥0; a≠1
e)A=\(\dfrac{x-1}{\sqrt{y}-1}\sqrt{\dfrac{\left(y-2\sqrt{y}+1\right)}{\left(x-1\right)^4}}\) với x≠1; y≠1; y>o
f)A=\(\sqrt{\dfrac{m}{1-2x+x^2}}\)\(\sqrt{\dfrac{4m-8mx+4mx^2}{81}}\) với m>0; x≠4
g)A=\(\left(\dfrac{\sqrt{x}+1}{x-4}-\dfrac{\sqrt{x}-1}{x+4\sqrt{x}+4}\right)\)\(\dfrac{x\sqrt{x}+2x-4\sqrt{x}-8}{\sqrt{x}}\) với x>0; x≠4
h)\(\left(\dfrac{1-a\sqrt{a}}{1-\sqrt{a}}+\sqrt{a}\right)\)\(\left(\dfrac{1-\sqrt{a}}{1-a}\right)^2\) với a≥0; a≠1
a: \(A=\dfrac{1}{2a-1}\cdot\sqrt{5a^2}\cdot\left|2a-1\right|\)
\(=\dfrac{2a-1}{2a-1}\cdot a\sqrt{5}=a\sqrt{5}\)(do a>1/2)
b: \(A=\dfrac{\sqrt{x-1-2\sqrt{x-1}+1}}{\sqrt{x-1}-1}+\dfrac{\sqrt{x-1+2\sqrt{x-1}+1}}{\sqrt{x-1}+1}\)
\(=\dfrac{\left|\sqrt{x-1}-1\right|}{\sqrt{x-1}-1}+\dfrac{\sqrt{x-1}+1}{\sqrt{x-1}+1}\)
\(=\dfrac{\sqrt{x-1}-1}{\sqrt{x-1}-1}+1=1+1=2\)
c:
\(=\dfrac{a+b}{b^2}\cdot\dfrac{ab^2}{a+b}=a\)
d: Sửa đề: \(A=\left(\dfrac{1-a\sqrt{a}}{1-\sqrt{a}}+\sqrt{a}\right)\left(\dfrac{1-\sqrt{a}}{1-a}\right)^2\)
\(=\left(1+\sqrt{a}+a+\sqrt{a}\right)\cdot\left(\dfrac{1}{1+\sqrt{a}}\right)^2\)
\(=\dfrac{\left(\sqrt{a}+1\right)^2}{\left(\sqrt{a}+1\right)^2}=1\)
e:
\(A=\dfrac{x-1}{\sqrt{y}-1}\cdot\sqrt{\dfrac{\left(\sqrt{y}-1\right)^2}{\left(x-1\right)^4}}\)
\(=\dfrac{x-1}{\sqrt{y}-1}\cdot\dfrac{\sqrt{y}-1}{\left(x-1\right)^2}=\dfrac{1}{x-1}\)
f:
\(A=\sqrt{\dfrac{m}{\left(1-x\right)^2}\cdot\dfrac{4m\left(1-2x+x^2\right)}{81}}\)
\(=\sqrt{\dfrac{m}{\left(x-1\right)^2}\cdot\dfrac{4m\left(x-1\right)^2}{81}}\)
\(=\sqrt{\dfrac{4m^2}{81}}=\dfrac{2m}{9}\)