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,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 

moi nguoi giup toi voi........cho ket qua thoi nha

1. gia tri x+y+z biet :

lx-5l+ly-4l+lz-4l=0

2.so cac uoc nguyen duong cu 2^6.3^3

3.so cac uoc nguyen duong cua 18

4.so duong thang tao thanh boi 8 biem phan biet doi mot khong thang hang

5.so tu nhien n thoa man 2^n+1:4^2=1024

6.UCLL(12,18,24)

7.so tu nhien n thoa man 2+4+6.......+n=110

8.tim x 576.15:x=540

9.gia tri a+b+c biet

a+b=10,a+c=25,b+c=25

so phan tu cua tap hop A cac so le nho hon 23