K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

13 tháng 7 2022

\(\left(a-b-c\right)-\left(a-c\right)=a-b-c-a+c=-b\\ \left(a+b\right)-\left(-a+b-c\right)=a+b+a-b+c=2a+c\\ -\left(a+b\right)+\left(a+b+c\right)=-a-b+a+b+c=c\\ \left(a+b-c\right)-\left(a-c\right)=a+b-c-a+c=b\\ \left(a+b\right)+\left(a-c-d+b\right)=a+b+a-c-d+b=2a+2b-c-d\\ -\left(a-b+c\right)+\left(a-b+d\right)=-a+b-c+a-b+d=-c+d\)

13 tháng 7 2022

b, =a-b-c-a+c=-b

b, =a+b+a-b+c=2a+c

b, =-a-a+a+b+c=a+b+c

c,= a+b-c-a+c=2a+b

c, =a+b+a-c-d+b=2a+2b-c-d

c, =-a+b-c+a-b+d=-c+d

\(a,\left(a-b+c-d\right)-\left(a+b+c+d\right)\)

\(=a-b+c-d-a-b-c-d\)

\(=-2b-2d\)

\(b,\left(-a+b-c\right)+\left(a-b\right)-\left(a-b+c\right)\)

\(=-a+b-c+a-b-a+b-c\)

\(=-a+b-2c\)

\(c,-\left(a-b-c\right)+\left(b-c+d\right)-\left(-a+b+d\right)\)

\(=-a+b+c+b-c+d+a-b-d\)

\(=b\)

10 tháng 6 2017

a) ( a - b + c -d ) - ( a+ b + c + d ) = a - b + c - d - a - b - c - d = -2b - 2d 

b) ( -a + b -c ) + ( a - b ) - ( a- b + c ) = -a + b - c + a - b - a + b - c = -a + b - c - c = -a + b - 2c 

c) - ( a - b - c ) + ( b - c + d ) - ( -a + b + d )

10 tháng 6 2017

a) (a-b+c-d)-(a+b+c+d)

=a-b+c-d-a-b-c-d

=-2b-2d

=2(b-d)

b) (-a+b-c)+(a-b)-(a-b+c)

=-a+b-c+a-b-a+b-c

=-a+b-2c

c) -(a-b-c)+(b-c+d)-(-a+b+d)

=-a+b+c+b-c+d+a-b-d

=b

17 tháng 12 2016

a) ( a + b + c ) - ( a - b - c )

= ( a + b + c ) - a + b + c

= a + ( - a ) + b + c + b + c

= 0 + b + c + b + c

= ( b + c ) x 2

b) ( a + b - c ) + ( a - b ) - ( a - b - c )

= ( a + b - c ) + a - b - a + b + c

= [ a + a + ( -a ) ] + [ b + ( -b ) + b ] + [ ( -c ) + c ]

= a + b + 0

= a + b

c) - ( a - b - c ) + ( -a + b - c ) - ( -a + b + c )

= ( -a ) + b + c + ( -a ) + b - c + a - b - c

= [ ( -a ) + ( -a ) + a ] + [ b + b + ( -b ) ] + [ c + ( -c ) + ( -c ) ]

= ( -a ) + b + ( -c )

17 tháng 12 2016

a , ( a + b + c ) - ( a - b - c )

= a + b + c - a + b + c

= ( a - a ) b + b + c + c

= 0 + b + b + c + c 

= 0 + 2b + 2c

= 0 + 2(b + c )

= 2(b+c)

b , ( a + b - c ) + ( a - b ) - ( a -  b - c )

= a + b - c + a - b - a + b + c

= ( a - a ) + b + b + ( - c + c )

= 0 + b + b + 0

= 2b

c , - ( a - b - c ) + ( - a + b - c ) - ( - a + b + c )

= - a + b + c - a + b - c + a - b - c

= ( - a + a ) + ( b - b ) + ( c - c ) + a + b

= 0 + 0 + 0 + a + b= a + b

16 tháng 1 2016
  1. A=a+b+c-d-a+b-c+d+a=a+2b

may cau sau tuong tu pha ngoac ra roi rut gon

 

 

16 tháng 1 2016

a,a+b+c-d-a+b-c+d+a=a+2b

b, -a+b-d+b-c+d+c-b-d=-a+b-d

c,a-b-c+d+b+c=a+d

9 tháng 1 2018

a) \(\left(a+b-c\right)-\left(b-c+d\right)\)

\(=a+b-c-b+c-d\)

\(=a+b-b-c+c-d\)

\(=a-d\)

b) \(-\left(a-b+c\right)+\left(a-b+d\right)\)

\(=\left(-a\right)+b-c+a+b-d\)

\(=\left(-a\right)+a+b+b-c-d\)

\(=2b-c-d\)

c) \(\left(a+b\right)-\left(-a+b-c\right)\)

\(=a+b+a-b+c\)

\(=a+a+b-b+c\)

\(=2a+c\)

d) \(-\left(a-b-c\right)+\left(a-b-c\right)\)

\(=-a+b+c+a+b+c\)

\(=-a+a+b+b+c+c\)

\(=2b+2c\)

(chắc hơi sai... > . < ...)

14 tháng 7 2017

a, \(\left(a+b+c+d\right)-\left(a-b+c-d\right)\)

\(=a+b+c+d-a+b-c+d=2b+2d\)

\(=2.\left(b+d\right)\)

b, \(\left(-a+b-c+d\right)+\left(a+d\right)+\left(-b+c\right)\)

\(=-a+b-c+d+a+d-b+c\)

\(=2d\)

c, \(-\left(a-b-d\right)+\left(b-c+d\right)-\left(-c+b-d\right)\)

\(=-a+b+d+b-c+d+c-b+d\)

\(=-a+b+3d\)

Chúc bạn học tốt!!!

14 tháng 7 2017

a,(a+b+c+d)-(a-b+c-d) = a + b + c + d - a + b - c + d = (a - a) + (b + b) + (c - c) + (d + d) = 2b + 2d = 2.(b + d)

b,(-a+b-c+d)+(a+d)+(-b+c) = -a + b - c + d + a + d - b + c = (-a + a) + (b - b) + ( -c + c) + (d + d) = 2d

c,-(a-b-d)+(b-c+d)-(-c+b-d)= -a + b + d + b - c + d + c - b + d = -a + (b + b - b) + (-c + c) + ( d + d + d) = -a + b + 3d

18 tháng 3 2020

\( a)\left( {a + b - c} \right) + \left( {b + c - a} \right) + \left( {a + c - b} \right)\\ = a + b - c + b + c - a + a + c - b\\ = a + b + c\\ b)\left( {a - b} \right) + \left( {b - c + a} \right) + \left( {c - b} \right)\\ = a - b + b - c + a + c - b\\ = 2a + b\\ c)\left( {2a - b + c} \right) + \left( {b - c + a} \right) + \left( {c - 2a + b} \right)\\ = 2a - b + c + b - c + a + c - 2a + b\\ = a + b + c\\ d)\left( {a - c + b} \right) + \left( {b - c - a} \right) - a - b - c\\ = a - c + b + b - c - a - a - b - c\\ = - a - b - 3c \)

18 tháng 3 2020

a) (a + b - c) + (b + c - a) + (a +​c - b)

= a + b - c + b + c - a + a + c - b

= (a - a + a) + (b - b + b) + (c - c + c)

= a + b + c

b) (a - b) + (b - c + a) + (c - b)

= a - b + b - c + a + c - b

= (a + a) + (b - b - b) + (c - c)

= 2a - b

c) (2a - b + c) + (b - c + a) + (c - 2a + b)

= 2a - b + c + b - c + a + c - 2a + b

= (2a - 2a) + (b - b + b) + (c - c + c)

= b + c

d) (a - c + b) + (b - c - a) - a - b - c

= a - c + b + b - c - a - a - b - c

= (a - a - a) + (b + b - b) - (c + c + c)

= b - 2a - 3c

Chúc bạn học tốt@@

7 tháng 8 2018

1) \(a\left(b-c-d\right)-a\left(b+c-d\right)\)

\(=ab-ac-ad-ab-ac+ad\)

\(=-2ac\)

2) \(\left(a+b\right)\left(c+d\right)-\left(a+d\right)\left(b+c\right)\)

\(=ac+ad+bc+bd-ab-ac-bd-cd\)

\(=ad+bc-ab-cd\)

3) \(\left(a+b\right)\left(c-d\right)-\left(a-b\right)\left(c+d\right)\)

\(=ac-ad+bc-bd-ac-ad+bc+bd\)

\(=-2ad+2bc\)

\(=-2\left(ad-bc\right)\)

30 tháng 12 2017

= -a+b+c+b-c+d-a-d

=(-a-a)+(b+b)+(c-c)+(d-d)

=-2a+2b

30 tháng 12 2017

- ( a-b-c ) + (b-c+d) - (a+d)

= -a + b +c +b - c +d -a -d

= -a + ( -a ) + b + b

= -a .2 + b.2