rut gon bieu thuc (6x-1)^2+(6x+1)^2-2(1+6x)(6x+1)
(4x-3)(3x+2)-(6x+1)(2x-5)+1
rut gon bieu thuc
12x2 + 8x - 9x - 6 - 12x2 + 30x + 2x -5 + 1= 31x - 10
rut gon bieu thuc (6x+7)(2x-3)-(4x+1)(3x-7/4)
Rut gon cac bieu thuc sau
A) 2x^2(1-3x)+6x^3
B) (x-y)^2+(x+y)^2+2(x-y)(x+y)
A) 2x2(1-3x)+6x3
=2x2*(1-3x)+2x2*3x
=2x2*(1-3x+3x)
=2x2
B) (x-y)2+(x+y)2+2(x-y)(x+y)
=2(x2-y2)+x2+2xy+y2+x2-2xy+y2
=2x2-2y2+x2+2xy+y2+x2-2xy+y2
=4x2
\(\dfrac{\left(x+2\right)^2}{x}\times\left(1-\dfrac{x^2}{x+2}\right)-\dfrac{x^2+6x+4}{x}\)
rut gon bieu thuc tren
\(=\dfrac{\left(x+2\right)^2}{x}\cdot\dfrac{x+2-x^2}{x+2}-\dfrac{x^2+6x+4}{x}\)
\(=\dfrac{\left(x+2\right)\left(-x^2+x+2\right)-x^2-6x-4}{x}\)
\(=\dfrac{-x^3+x^2+2x-2x^2+2x+4-x^2-6x-4}{x}\)
\(=\dfrac{-x^3-2x^2-2x}{x}=-x^2-2x-2\)
Rut gon bieu thuc:
2(2x-3)^2+(x-2)(x+2)
(12x^2y^2-6x^3y^2):3x^2y:-4y(2x-5)
\(\frac{x+3}{x^2-4}.\frac{8-12x+6x^2-x^3}{9x+27}\)
rut gon bieu thuc
\(\frac{x+3}{x^2-4}.\frac{8-12x+6^2-x^3}{9x+27}\)
\(=\frac{x+3}{x^2-4}.\frac{-x^3+6x^2-4}{9x+27}\)
\(=\frac{\left(x+3\right)\left(-x^3+6x^2-4\right)}{\left(x^2-4\right)\left(9x+27\right)}\)
\(=\frac{\left(x+3\right)\left(-x^3+6x-4\right)}{9\left(x+3\right)\left(x^2-4\right)}\)
\(=\frac{-x^3+6x^2-4}{9\left(x^2-4\right)}\)
Mk ko chắc
(x+3 )/ (x-2)(x+2) . [(2-x)^3 / 9(x+3)]
= -(x-2)^2 / [(x+2).9]
Giúp mình nhé!!
2. Rut gon bieu thuc:
a) \(A=\sqrt{x-2+2\sqrt{x-3}}+\sqrt{x+6+6\sqrt{x-3}},voix>=3\)
3. Tim GTNN cua bieu thuc:
a) \(A=\sqrt{4x^2-12x+9}+\sqrt{x^2-10x+25}+\sqrt{9x^2-6x+1}+\sqrt{16x^2-72x+81}\)
b) \(B=\dfrac{1}{2}\sqrt{x^2}+\sqrt{x^2-2x+1}\)
Giup minh nhe!!
1. Rut gon bieu thuc:
a) \(A=\sqrt{11-6\sqrt{2}}+3+\sqrt{2}\)
b) \(B=\sqrt{12+2\sqrt{11}}+\sqrt{12-2\sqrt{11}}\)
2. Rut gon bieu thuc:
a) \(A=\sqrt{x-2+2\sqrt{x-3}}+\sqrt{x+6+6\sqrt{x-3}},voix>=3\)
3. Tim GTNN cua bieu thuc:
a) \(A=\sqrt{4x^2-12x+9}+\sqrt{x^2-10x+25}+\sqrt{9x^2-6x+1}+\sqrt{16x^2-72x+81}\)
b) \(B=\dfrac{1}{2}\sqrt{x^2}+\sqrt{x^2-2x+1}\)
1)
a)
\(\sqrt{11-6\sqrt{2}}=\sqrt{2-2.3.\sqrt{2}+9}=\left|\sqrt{2}-3\right|=3-\sqrt{2}\)
\(A=3-\sqrt{2}+3+\sqrt{2}=6\)
b)
\(B^2=24+2\sqrt{12^2-4.11}=24+2\sqrt{100}=24+20=44\)
\(B=\sqrt{44}=2\sqrt{11}\)
rut gon phan thuc A=(x^3-6x+7)/(x^3+5x^2-2x-24)