Question

1 Bỏ ngoặc tính rồi thu gọn;

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

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

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

Answer 1

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!!!

Answer 2

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

Answer 3

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

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

\(=2b+2d\)

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

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

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

\(=2d\)

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

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

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