\(VT=-a-b-c-1+b-c-a+c+1\)
\(=-c-2a=VP\)
VẬY ....
Ta có
\(VT:-\left(a+b+c+1\right)+\left(b-c\right)-\left(a-c-1\right)\)
\(\Leftrightarrow-a-b-c-1+b-c-a+c+1\)
\(\Leftrightarrow-2a-c=VT\)
\(\Rightarrow-\left(a+b+c+1\right)+\left(b-c\right)-\left(a-c-1\right)=-c-2a\left(đpcm\right)\)
Bài này bạn chỉ cần phá ngoặc ra và tính là đc
\(\text{Chứng minh đẳng thức}:\)
\(\left(a+b\right)-\left(b-a\right)+c=2a+c\)
Chứng minh đẳng thức
\(\left(a-c\right)\left(b+d\right)-\left(a-d\right)\left(b+c\right)=\left(a+b\right)\left(d-c\right)\)
Chứng minh các đẳng thức sau:
a) \(\left(a+b\right)-\left(-a+b-c\right)+\left(c-a-b\right)=a-b+2c\)+ 2c
b) \(a\left(b-c\right)-a\left(b+d\right)=-a\left(c+d\right)\)
Chứng minh đẳng thức:
a) \(\left(a+b\right)\left(c+d\right)-\left(a+d\right)\left(b+c\right)=\left(a-c\right)\left(d-b\right)\)
b) \(\left(a-c\right)\left(b+d\right)-\left(a-d\right)\left(b+c\right)=\left(a+b\right)\left(d-c\right)\)
Chứng minh đẳng thức
a) \(\left(x-y\right)-\left(x-z\right)=\left(z+x\right)-\left(y+x\right)\)
b) \(\left(x-y+z\right)-\left(y+z-x\right)-\left(x-y\right)=\left(z-y\right)-\left(z-x\right)\)
c) \(a\left(b+c\right)-b\left(a-c\right)=\left(a+b\right)c\)
d) \(a\left(b-c\right)-a\left(b+d\right)=-a\left(c+d\right)\)
e) \(\left(a+b\right)\left(c+d\right)-\left(a+d\right)\left(b+c\right)=\left(a-c\right)\left(d-b\right)\)
f) \(\left(a-c\right)\left(b+d\right)-\left(a-d\right)\left(b+c\right)=\left(a+b\right)\left(d-c\right)\)
chứng minh đẳng thức: \(\frac{\left(a-b\right)^4}{\left(c-d\right)^4}=\frac{a^4+b^4}{c^4+d^4}\) biết \(\frac{a}{b}=\frac{c}{d}\)
Tính giá trị biểu thức:
\(a,A=\left(-1\right).\left(-1\right)^2.\left(-1^3\right).\left(-1\right)^4...........\left(-1\right)^{2016}.\left(-1\right)^{2017}\)
\(b,B=70.\left(\frac{131313}{565656}+\frac{131313}{727272}+\frac{131313}{909090}\right)\)
\(c,C=\frac{2a}{3b}+\frac{3b}{4c}+\frac{4c}{5d}+\frac{5d}{2a}\)
biết\(\frac{2a}{3b}=\frac{3b}{4c}=\frac{4c}{5d}=\frac{5d}{2a}\)
Bỏ dấu ngoặc rồi thu gọn biểu thức :
a, \(A=\left(a-2b+c\right)-\left(a-2b-c\right)\)
b, \(B=\left(-x-y+3\right)-\left(-x+2-y\right)\)
c, \(C=2.\left(3a+b-1\right)-3\left(2a+b-2\right)\)
