A= (3,1 - 2,5) - (-2,5 + 3,1)

=3.1-2.5+2.5-3.1

=0

B= (5,3 - 2,8) - (4 + 5,3)

=5.3 - 2.8-4-5.3

= -6.8

C= -(251.3 + 281) + 3.251 - (1-281)

=-251.3-281+3.251-1+281

=-1

D= -(3/5+3/4)−(−3/4+2/5)

= -3/5-3/4+3/4-2/5

= -5/5

=-1

\(A=\left(3,1-2,5\right)-\left(-2,5+3,1\right)=3,1-2,5+2,5-3,1=0\)

\(B=\left(5,3-2,8\right)-\left(4+5,3\right)=5,3-2,8-4-5,3=-6,8\)

\(C=-\left(215\cdot3+281\right)+3\cdot215-\left(1-281\right)=-215\cdot3-281+3\cdot215-1+281=1\)

\(D=-\left(\frac{3}{5}+\frac{3}{4}\right)-\left(-\frac{3}{4}+\frac{2}{5}\right)=-\frac{3}{5}-\frac{3}{4}+\frac{3}{4}-\frac{2}{5}=-1\)

\(A=\left(3,1-2,5\right)-\left(-2,5+3,1\right)\)

\(A=3,1-2,5+2,5-3,1\)

\(A=\left(3,1-3,1\right)-\left(2,5-2,5\right)\)

\(A=0-0\)

\(A=0\)

\(B=\left(5,3-2,8\right)-\left(4+5,3\right)\)

\(B=5,3-2,8-4-5,3\)

\(B=\left(5,3-5,3\right)-\left(2,8+4\right)\\ B=0-6,8\\ B=-6,8\)

-(251.3+281)+3.251-(1-281)=-(251.3+281)+(3.251+1+281)=1(vì (3.251+1+281)-1 là số đối của -(251.3+281)

đunga nha Vương Thảo

Minh sai rồi

Phải = -1 chứ

A = \(\left(3,1-2,5\right)-\left(-2,5+3,1\right)\)

\(=3,1-2,5+2,5-3,1=6,2\)

B = \(\left(5,3-2,8\right)-\left(4+5,3\right)\)

\(=5,3-2,8-4-5,3=-6,8\)

C = \(-\left(251.3+281\right)+3.251-\left(1-281\right)\)

\(=-251.3-281+3.251-1+281=-1\)

D = \(-\left(\frac{3}{5}+\frac{3}{4}\right)-\left(-\frac{3}{4}+\frac{2}{5}\right)\)

\(=-\frac{3}{5}-\frac{3}{4}+\frac{3}{4}-\frac{2}{5}=-1\)

(Nhớ k cho mình với nhá!)

- ( 251 . 3 + 281 ) + 3 . 251 - ( 1 - 281 )

= - ( 753 + 281 ) + 753 - 1 + 281

= - 753 - 281 + 753 - 1 + 281

= ( -753 + 753 ) - ( -281 + 281 ) - 1 

= 0 - 0 - 1 = -1 

\(B=-\left(251+281\right)+3,251-\left(1-281\right)\)

\(B=-532+3,251-\left(1-28\right)\)

\(B=-532+3,251-\left(-27\right)\)

\(B=3783-\left(-27\right)\)

\(B=3810\)

-(251.3+281)+3.251-(1-281)

=-251.3-281+3.251-1+281

=-1

Dễ ợt thế này mà

sai ngay từ vòng gửi xe

Ta có :

-251.3-281+3.251-1+281

=-281-1+281

=-1

:)) đây nhé bạn

\(-\left(251.3+281\right)+3.251-\left(1-281\right)\)

\(=-251.3-281+3.251-1+281\)

\(=3.\left(251-251\right)+\left(-281+281\right)-1\)

\(=3.0+0-1\)

\(=-1\)

B= (-251.3+281)+3.251 -(1-281)

B=(-753+281)+753-(-280)

B=-472+753+280

B= 281+280

B= 561