cho a+b+c=0. Rut gon M= a^3+b^3+c(a^2+b^2)-abc
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Cho a+b+c=0. Rut gon bieu thuc M=a3+b3+c(a2+b2)-abc
a+b+c=0 <=> c = -a-b
M = a3+b3+c(a2+b2)-abc
M = a3+b3+(-a-b)(a2+b2)-abc
M = a3+b3-a3-a2b-ab2-b3-abc
M = -a2b-ab2-abc
M = -ab(a+b+c)
M = -ab.0 = 0
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Cho cac so nguyen duong a,b,c,x,y,z1, Biet 1/a 3/b + c 5/c + a. Hay rut gon phan so A a/2b - c2. Biet a/b 2b/cc 4c/a. Hay rut gon phan so B ab + bc + ca/a2 + b + c23. Biet x/a y/b z/c. Hay rut gon phan so C x*y*z*(b+c)*(c+a)*(a+b)/a*b*c(y+z)*(z+x)*(x+y)4. Biet ab/a + 2b 2/5; bc/b + 2c 3/4; ca/c +2a 3/5. Hay rut gon phan so D abc/ab+bc+ca5. Biet 3/a -4b 5c. Hay rut gon phan so E 3bc + ab - 4ac/6bc - 8ac -abGiup minh nhe! Ai lam duoc va dung cho tick.Thanks cac ban
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Cho cac so nguyen duong a,b,c,x,y,z
1, Biet 1/a = 3/b + c = 5/c + a. Hay rut gon phan so A = a/2b - c
2. Biet a/b = 2b/cc = 4c/a. Hay rut gon phan so B = ab + bc + ca/a2 + b + c2
3. Biet x/a = y/b =z/c. Hay rut gon phan so C = x*y*z*(b+c)*(c+a)*(a+b)/a*b*c(y+z)*(z+x)*(x+y)
4. Biet ab/a + 2b = 2/5; bc/b + 2c = 3/4; ca/c +2a = 3/5. Hay rut gon phan so D = abc/ab+bc+ca
5. Biet 3/a -4b = 5c. Hay rut gon phan so E = 3bc + ab - 4ac/6bc - 8ac -ab
Giup minh nhe! Ai lam duoc va dung cho tick.
Thanks cac ban
xin lỗi tớ ấn nhầm chỗ M=7 tớ làm lại rồi đó
ban tra loi het cac cau hoi phia tren kia ho minh dc ko?
Cho cac so nguyen duong a,b,c,x,y,z1, Biet 1/a 3/b + c 5/c + a. Hay rut gon phan so A a/2b - c2. Biet a/b 2b/cc 4c/a. Hay rut gon phan so B ab + bc + ca/a2 + b + c23. Biet x/a y/b z/c. Hay rut gon phan so C x*y*z*(b+c)*(c+a)*(a+b)/a*b*c(y+z)*(z+x)*(x+y)4. Biet ab/a + 2b 2/5; bc/b + 2c 3/4; ca/c +2a 3/5. Hay rut gon phan so D abc/ab+bc+ca5. Biet 3/a -4b 5c. Hay rut gon phan so E 3bc + ab - 4ac/6bc - 8ac -abGiup minh nhe! Ai lam duoc va dung cho tick.Thanks cac ban
Đọc tiếp
Cho cac so nguyen duong a,b,c,x,y,z
1, Biet 1/a = 3/b + c = 5/c + a. Hay rut gon phan so A = a/2b - c
2. Biet a/b = 2b/cc = 4c/a. Hay rut gon phan so B = ab + bc + ca/a2 + b + c2
3. Biet x/a = y/b =z/c. Hay rut gon phan so C = x*y*z*(b+c)*(c+a)*(a+b)/a*b*c(y+z)*(z+x)*(x+y)
4. Biet ab/a + 2b = 2/5; bc/b + 2c = 3/4; ca/c +2a = 3/5. Hay rut gon phan so D = abc/ab+bc+ca
5. Biet 3/a -4b = 5c. Hay rut gon phan so E = 3bc + ab - 4ac/6bc - 8ac -ab
Giup minh nhe! Ai lam duoc va dung cho tick.
Thanks cac ban
Cho cac so nguyen duong a,b,c,x,y,z1, Biet 1/a 3/b + c 5/c + a. Hay rut gon phan so A a/2b - c2. Biet a/b 2b/cc 4c/a. Hay rut gon phan so B ab + bc + ca/a2 + b + c23. Biet x/a y/b z/c. Hay rut gon phan so C x*y*z*(b+c)*(c+a)*(a+b)/a*b*c(y+z)*(z+x)*(x+y)4. Biet ab/a + 2b 2/5; bc/b + 2c 3/4; ca/c +2a 3/5. Hay rut gon phan so D abc/ab+bc+ca5. Biet 3/a -4b 5c. Hay rut gon phan so E 3bc + ab - 4ac/6bc - 8ac -abGiup minh nhe! Ai lam duoc va dung cho tick.Thanks cac ban
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Cho cac so nguyen duong a,b,c,x,y,z
1, Biet 1/a = 3/b + c = 5/c + a. Hay rut gon phan so A = a/2b - c
2. Biet a/b = 2b/cc = 4c/a. Hay rut gon phan so B = ab + bc + ca/a2 + b + c2
3. Biet x/a = y/b =z/c. Hay rut gon phan so C = x*y*z*(b+c)*(c+a)*(a+b)/a*b*c(y+z)*(z+x)*(x+y)
4. Biet ab/a + 2b = 2/5; bc/b + 2c = 3/4; ca/c +2a = 3/5. Hay rut gon phan so D = abc/ab+bc+ca
5. Biet 3/a -4b = 5c. Hay rut gon phan so E = 3bc + ab - 4ac/6bc - 8ac -ab
Giup minh nhe! Ai lam duoc va dung cho tick.
Thanks cac ban
Cac ban tra loi giup minh di, minh se cho nhieu k!
Please.....!
Cho x/a =y/b =z/c va a b c x y z khac 0 rut gon bieu thuc b = ( a^2x + b^2y + c^2z ) / x^3 +y^3+z^3
rut gon
M= (a-b)^3 + (b-c)^3 + (c-a)^3 /(a-b)(b-c)(c-a)
\(M=\dfrac{\left(a-b+b-c\right)^3-3\left(a-b\right)\left(b-c\right)\left(a-b+b-c\right)+\left(c-a\right)^3}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}\)
\(=\dfrac{-3\left(a-b\right)\left(b-c\right)\left(a-c\right)}{\left(a-b\right)\left(b-c\right)\left(c-a\right)}=-3\)
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Rut gon phan thuc
\(M=\frac{\left(b-c\right)^3+\left(c-a\right)^3+\left(a-b\right)^3}{a^2\left(b-c\right)+b^2\left(c-a\right)+c^2\left(a-b\right)}\)
a^3 + b^3 + 3abc - c^3 / (a+b)^2 - c^2 rut gon phan thuc dai so
cho A=\(\dfrac{1}{b^2+c^2-a^2}+\dfrac{1}{c^2+a^2-b^2}+\dfrac{1}{a^2+b^2-c^2}\)
rut gon A biet a+b+c=0
Từ \(a+b+c=0\Rightarrow\left\{{}\begin{matrix}a+b=-c\\a+c=-b\\b+c=-a\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a^2+2ab+b^2=c^2\\a^2+2ac+c^2=b^2\\b^2+2bc+c^2=a^2\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}a^2+b^2-c^2=-2ab\\a^2+c^2-c^2=-2ac\\b^2+c^2-a^2=-2bc\\\end{matrix}\right.\)
\(\Rightarrow A=\dfrac{1}{-2ab}+\dfrac{1}{-2ac}+\dfrac{1}{-2bc}=\dfrac{a+b+c}{-2abc}=\dfrac{0}{-2abc}=0\)
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