- Bằng \(\dfrac{5}{211}\)

gọi 1/547=a, 1/211=b ta đc:

\(2a.3b-546a.b-4ab< =>6ab-546ab-4ab=-544ab=\dfrac{-544}{547.211}\)

=>\(B=\left(2\cdot\frac{1}{547}\cdot\frac{3}{211}\right)-\left(\frac{546}{547}\cdot\frac{1}{211}\right)-\left(\frac{4}{547\cdot211}\right)\)

=>\(B=\frac{6}{547\cdot211}-\frac{546}{547\cdot211}-\frac{4}{547\cdot211}\)

=>\(B=\frac{6}{115417}-\frac{546}{115417}-\frac{4}{115417}\)

=>\(B=\frac{-544}{115417}\)

M = \(2.\frac{1}{547}.\frac{3}{211}-\frac{546}{547}.\frac{1}{211}-\frac{1}{247.211}\)

M = \(\frac{6}{547.211}-\frac{546}{547.211}-\frac{4}{547.211}\)

M = \(\frac{-544}{547.211}\)

\(M=2.\frac{1}{547}.\frac{3}{211}-\frac{546}{547}.\frac{1}{211}-\frac{4}{547.211}\)

\(M=\left(2.\frac{1}{547}.\frac{3}{211}\right)-\left(\frac{546}{547}.\frac{1}{211}\right)-\left(\frac{4}{547.211}\right)\)

\(M=\frac{6}{547.211}-\frac{546}{547.211}-\frac{4}{547.211}\)

\(M=\frac{6}{115417}-\frac{546}{115417}-\frac{4}{115417}\)

\(M=\frac{-540}{115417}-\frac{4}{115417}\)

\(M=\frac{-544}{115417}\)

đề bài hơi khó hiểu nha

\(2\dfrac{1}{547}.\dfrac{3}{211}-\dfrac{546}{547}.\dfrac{1}{211}-\dfrac{4}{547.211}\)

\(=\left(2+\dfrac{1}{547}\right).3.\dfrac{1}{211}-\left(1-\dfrac{1}{547}\right).\dfrac{1}{211}-4.\dfrac{1}{547}.\dfrac{1}{211}\)

Đặt \(a=\dfrac{1}{547};b=\dfrac{1}{211}\)

Thay \(a=\dfrac{1}{547};b=\dfrac{1}{211}\) vào biểu thức trên , ta được :

\(\left(2+a\right).3b-\left(1-a\right)b-4ab\)

\(=6b+3ab-b+ab-4ab\)

\(=5b\)

\(=5.\dfrac{1}{211}\)

\(=\dfrac{5}{211}\)

Vậy g/t biểu thức trên là : \(\dfrac{5}{211}\)

\(-\frac{544}{115417}\)

\(-\frac{544}{115417}\)

#Hok_tốt

Kq mk giống bn Nguyễn Ngọc Quý nha

Nhớ k mk nha

Học tốt

a: \(M=\dfrac{631}{315}\cdot\dfrac{1}{651}-\dfrac{1}{105}\cdot\dfrac{2603}{651}-\dfrac{4}{315\cdot651}+\dfrac{4}{105}\)

\(=\dfrac{1}{315\cdot651}\cdot\left(631-4\right)-\dfrac{1}{105}\left(\dfrac{2603}{651}-4\right)\)

\(=\dfrac{1}{105}\cdot\dfrac{1}{1953}\cdot627+\dfrac{1}{105\cdot651}\)

\(=\dfrac{1}{105\cdot651}\left(\dfrac{1}{3}\cdot627+1\right)=\dfrac{1}{105\cdot651}\cdot210=\dfrac{2}{651}\)

b: \(N=\dfrac{1095}{547}\cdot\dfrac{3}{211}-\dfrac{546}{547\cdot211}-\dfrac{4}{547\cdot211}\)

\(=\dfrac{1}{547\cdot211}\left(1095\cdot3-546-4\right)\)

\(=\dfrac{1}{547\cdot211}\cdot2735=\dfrac{5}{211}\)

A = (x - 1) (x² - 2x + 1) + 4x(x + 1)(x - 1) - 3(1 - x)(x² + x + 1)

= (x - 1) (x² - 2x + 1) + 4x(x + 1)(x - 1) + 3(x - 1)(x² + x + 1)

= (x - 1) [x² - 2x + 1 + 3(x² + x + 1) + 4x(x + 1)]

= (x - 1) (x² - 2x + 1 +3x² + 3x + 3 + 4x² + 4x)

= (x - 1) (8x² + 5x + 4)

Vậy A = (x - 1) (8x² + 5x + 4)