a,\(\frac{x}{y}=\frac{7}{3}\Rightarrow\frac{x}{7}=\frac{y}{3}\Rightarrow\frac{5x}{35}=\frac{2y}{6}=\frac{5x-2y}{35-6}=\frac{87}{29}=3\)
=> x = 21; y = 9
b, \(\frac{x}{19}=\frac{y}{21}\Rightarrow\frac{2x}{38}=\frac{y}{21}=\frac{2x-y}{38-21}=\frac{34}{17}=2\)
=> x = 38; y = 42
tim x,y biet :a)x/y =7/3 va 5x -2y -87 b)x/19 = y/21 va 2x -y =34
Ti le thuc x y ti le voi 2 3 va x+y =-15
X÷y=7÷20 y÷z=7÷3 va y-x-z=62
3/y=7/x va x+16=y
X y ti le voi 5;3 va x^2-y^2=4
5x=8y=20z va x-y-z=3
3x=2y;7y =5z va 2x+y-z=-28
2x/3=3y/4=4z/5 va 3x-4y+5z=65
19/21<x/y<7/6 3x-2y=5 Tìm x va y
Tìm x; y ; z
A, x /10 = y/6 = z/21 va 5x + y - 2x = 28
B, x / 3 = y /4 , y/5 =z/7 va 2x + 3y -z =124
a, x/5=y/3 và 5x-3y=8
b, x/3=y/4 ; y/5 = z/7 va 2x+ 3y-z=124
c, 3x=2y ; 7y=5z va x-y+z=32
đ, 2x/3=3y/4=4z/5 và x+y+z=49
e, 2x=3y=5z va x+y-z=95
f, x-1/2=y-2/3=z-3/4 va 2x+3y-z=50
a) x/5=y/3 va x+y= -48
b) x/-3 = y/2 va 2x-5y = -32
c) x/4=y/-5 va -3x + 2y=55
d) 5x=2uy ; 3uy=5z va x+y+z =-72
b2:tìm x,y,z
a) x/3=y/4=z/5 va 2x+3y+5z=86
b) x/3=y/4; y/6=z/8 va 3x-2y-z=13
c) x/2=y'3=z/4 va xy+yz+zx=104
b3:tìm x,y,z
a)x/3=y/7=z/2 va 2x^2 +y^2 +3z^2=316
b)x:y:z=2:5:7 va 3x+2y-z=27
Tim x,y,z
a/ \(\frac{x}{y}\)=\(\frac{7}{3}\)va 5x-2y=87
b/\(\frac{x}{19}\)=\(\frac{y}{21}\)và 2x-y=34
c/\(\frac{x^3}{8}\)=\(\frac{y^3}{64}\)=\(\frac{z^3}{216}\)va \(x^2\)+\(y^2\)+\(z^2\)=14
đ/\(\frac{2x+1}{5}\)=\(\frac{3y-2}{7}\)=\(\frac{2x+3y-1}{6x}\)
tìm x ,y ,z biết
a, x /5 =y/3 ; y/2 =z/7 va 5x +y -2x =28
b, x/3 =y /4 =z/5 va z-x = -6
