yx3+y/2+y/4=11/2:y

yx3+y:2+y:4=5,5:y

yx3+y:(2+4)=5.5:y

yx3+y:6=5,5:y

yx3+yx1/6=5,5:y

yx(3+1/6)=5,5:y

yx19/6=5,5:y

...........................

bn ơi là 1\(\frac{1}{2}\)

 Yx(7+1-3+5)=7800
Yx10=7800
Y=7800:10
Y=780
 

+) Ta có: yz-xy=42+30

           =>y(z-x)=72

           =>-12y  =72

           =>y       =-6

+) Mà x.y=-30

  =>x.(-6)=-30

  =>x      =5

         y.z=42

   =>-6.z=42

   =>z    =-7

Vậy (x;y;z)=(5;-6;-7)

y x 3 + y : 2 = 110

y x 3 + y x 0,5 = 110

y x ( 3 + 0,5 ) = 110

y x 3,5 = 110

y = 110 : 3,5

y = ??????????

Ta có: \(\hept{\begin{cases}\frac{x}{y}=-30\\\frac{y}{z}=42\\z-x=-12\end{cases}}\).
Suy ra \(\frac{x}{y}.\frac{y}{z}=-30.42\Leftrightarrow\frac{x}{z}=-1260\) suy ra \(x=-1260.z\).
Suy ra \(z-x=z-\left(-1260z\right)=z\left(1+1260\right)=12\).
Suy ra \(z=\frac{12}{1261}\).
Vậy \(y=42.z=42.\frac{12}{1261}=\frac{504}{1256}\).
\(x=30.y=30.\frac{12}{1261}=\frac{360}{1261}\).
 

yx3=246-12

yx3=234

y=234:3

y=78

y:3+5=215

y:3=215-5

y:3=210

y=210x3

y=630

y x 3= 246 - 12

3y= 246 -12

3y= 234 = 78

y= 78

+) \(Y\times3=246-12\)

    \(Y\times3=234\)

    \(Y=78\)

+) \(Y:3+5=215\)

    \(Y:3=210\)

    \(Y=630\)

672/(y*3)=8

=>y*3=672/8

=>y*3=84

=>y=84/3=28

Yx7+Yx3 =60

Y x (7+3)=60

Yx10=60

Y=60:10

Y=6

7y+3y=60

10y=60

y=6

Y x 7 + Y x 3 = 60

Y x (7 + 3) = 60

Y x 10 = 60

Y = 60 : 10

Y = 6 

x×y=-30 ,y×z=42

=>x×y/y×z=-30÷42

=>x/z=-5/7

=>x/-5=z/7=z-x/7+5=-12/12=-1

=>x=-5×-1=5

    z=7×-1=-7

=>5y=-30

=>y=-6

Vậy x=5,y==

Nhớ tk thật nhiều cho mk nha!!!😉