Thu gọn các tổng sau:
a) (a –b + c- d) – ( a+ b-+c+d)
b) ( -a + b – c) + ( a – b) – (a – b + c)
c) – ( a- b- c) + ( b – c+d) – ( a-b +c)
Thu gọn các tổng sau:
a) (a - b + c - d) - (a + b + c + d)
b) (-a + b - c) + (a - b) - (a - b + c)
\(a,=a-b+c-d-a-b-c-d=-2b-2d\\ b,=-a+b-c+a-b-a+b-c=-a+b-2c\)
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 )
Rút gọn các tổng sau:
a, (a - b + c - d) - (a +b + c + d)
b, (- a + b - c) + (a - b) - (a - b - c)
c, - (a - b - c) + (b - c + d) - ( - a + b + d)
a) = a - b + c - d - a - b - c - d
= -2b - 2d
b) = -a + b - c + a - b - a + b + c
= -a + b
c) = -a + b + c + b - c + d + a - b - d
= b
a) = a - b + c - d - a - b - c - d
= -2b - 2d
b) = -a + b - c + a - b - a + b + c
= -a + b
c) = -a + b + c + b - c + d + a - b - d
= b
Bỏ dấu ngoặc rồi thu gọn các tổng sau
A, (a+b+c-d) -(a+b+c+d)
B, (-a+B-C) +(A-B) -(A-B+c)
C, -(a-b-c)+(B-C+D) -(-a+b+D)
( *¯ ³¯*)♡
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)
= 0 + 0 + 0 - 2d
= -2d
Ý b, c em xem lại xem sao chỗ chữ cái viết hoa chỗ lại viết thường là sao em nhỉ?
Cô oi chữ nó bị thế thoi, A và a giống nhau cô ah
Thu gọn các tổng sau:
a) ( a - b + c - d ) - ( a + b + c + d )
b) (-a + b - c ) + ( a- b ) - ( a- b + c)
c) - ( a -b - c ) + ( b - c + d ) - ( -a + b + d )
Các bạn giúp mình mai nộp rồi
\(a,\left(a-b+c-d\right)-\left(a+b+c+d\right)\)
\(=a-b+c-d-a-b-c-d\)
\(=-2b-2d\)
\(b,\left(-a+b-c\right)+\left(a-b\right)-\left(a-b+c\right)\)
\(=-a+b-c+a-b-a+b-c\)
\(=-a+b-2c\)
\(c,-\left(a-b-c\right)+\left(b-c+d\right)-\left(-a+b+d\right)\)
\(=-a+b+c+b-c+d+a-b-d\)
\(=b\)
Thu gọn tổng sau :
a) ( a - b + c -d ) - ( a+ b + c + d )
b) ( -a + b -c ) + ( a - b ) - ( a- b + c )
c) - ( a - b - c ) + ( b - c + d ) - ( -a + b + d )
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 )
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
Bỏ dấu ngoặc rồi thu gọn các biểu thức
1 (a – b + c) – (a + c)
2 (a + b) – (b – a) + c
3 - (a + b – c) + (a – b – c)
4 a(b + c) – a(b + d) - a(c – d)
5 a(b – c) + a(d + c) = a(b + d)
Giup mik với
1: =a-b+c-a-c=-b
2: =a+b-b+a+c=2a+c
3: =-a-b+c+a-b-c=-2b
4: =ab+ac-ab-ad-ac+ad=0
Thu gọn
a. A=(a+b+c-d)-(a-b+c-d)+a
b. B=-(a-b-d)+(b-c+d)-(-c+b+d)
c. C=(a-b)-(c-d)+(b+c)
may cau sau tuong tu pha ngoac ra roi rut gon
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
Từ tỉ lệ thức a/b=c/d (a,b,c,d khác 0;a khác \(\pm b\);c\(\ne\)\(\pm d\)) hãy suy ra các tỉ lệ thức sau:
a,\(\dfrac{a+b}{b}\) = \(\dfrac{c+d}{d}\)
b,\(\dfrac{a-b}{b}\) = \(\dfrac{c-d}{d}\)
c,\(\dfrac{a+b}{a}\) = \(\dfrac{c+d}{c}\)
d,\(\dfrac{a-b}{a}\) =\(\dfrac{c-d}{c}\)
e,\(\dfrac{a}{a+b}=\dfrac{c}{c+d}\)
f,\(\dfrac{a}{a-b}=\dfrac{c}{c-d}\)
a) \(\dfrac{a}{b}=\dfrac{c}{d}=k\Rightarrow\left\{{}\begin{matrix}a=bk\\c=dk\end{matrix}\right.\)
\(\Rightarrow\dfrac{a+b}{b}=\dfrac{bk+b}{b}=\dfrac{b\left(k+1\right)}{b}=k+1\) và \(\dfrac{c+d}{d}=\dfrac{dk+d}{d}=\dfrac{d\left(k+1\right)}{d}=k+1\)
\(\Rightarrow\dfrac{a+b}{b}=\dfrac{c+d}{d}\)
b) \(\dfrac{a}{b}=\dfrac{c}{d}=k\Rightarrow\left\{{}\begin{matrix}a=bk\\c=dk\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\dfrac{a-b}{b}=\dfrac{b\left(k-1\right)}{b}=k-1\\\dfrac{c-d}{d}=\dfrac{d\left(k-1\right)}{d}=k-1\end{matrix}\right.\)\(\Rightarrow\dfrac{a-b}{b}=\dfrac{c-d}{d}\)
c) \(\dfrac{a}{b}=\dfrac{c}{d}\Rightarrow\dfrac{a}{c}=\dfrac{b}{d}=\dfrac{a+b}{c+d}\Rightarrow\dfrac{a}{c}=\dfrac{a+b}{c+d}\Rightarrow\dfrac{a+b}{a}=\dfrac{c+d}{c}\)
d) \(\dfrac{a}{b}=\dfrac{c}{d}\Rightarrow\dfrac{a}{c}=\dfrac{b}{d}=\dfrac{a-b}{c-d}\Rightarrow\dfrac{a}{c}=\dfrac{a-b}{c-d}\Rightarrow\dfrac{a-b}{a}=\dfrac{c-d}{c}\)
e: Ta có: \(\dfrac{a}{b}=\dfrac{c}{d}\)
nên \(\dfrac{a}{c}=\dfrac{b}{d}\)
Áp dụng tính chất của dãy tỉ số bằng nhau, ta được:
\(\dfrac{a}{c}=\dfrac{b}{d}=\dfrac{a+b}{c+d}\)
hay \(\dfrac{a}{a+b}=\dfrac{c}{c+d}\)
Thu gọn biểu thức: a. (a – b – d) + (b – a + d)
b. – (a – b + c) – (a – b – c)
c. (c – a + d) + (a – b – d)