1

y=4/3

\(7+y=\frac{25}{3}\)

\(y=\frac{25}{3}-7\)

\(y=\frac{4}{3}\)

7 + y = 25/3 

y = 25/3 - 7 

y = 1/1/3 = > 4/3 

ta có:

\(-\frac{x}{2}=\frac{-y}{4}=\frac{6}{-8}\)

=>\(\frac{-x}{2}=\frac{6}{-8}\)

=>-8.(-x)=6.2

=>8x=12

=>x=3/2

lại có:

\(\frac{-y}{4}=\frac{6}{-8}\)

=>-8.(-y)=6.4

=>8y=24

=>y=3

Vậy x=3/2; y=3

làm như thế này mới nhanh

\(\frac{-x}{2}=\frac{-y}{4}=\frac{6}{-8}\)

=>\(\frac{-x}{2}=-y=\frac{6.4}{-8}\)

=>\(\frac{-x}{2}=-y=-3\)

=>\(\frac{-x}{2}=\frac{-3}{1}=>-x=\frac{-3.2}{1}=-6\)

=>x=-6 ;y=-3

Ta có 3n - 2n chia hết cho n + 1

=> n chia hết cho n + 1

=> n = 0

Ta có 3n - 2n chia hết cho n + 1

\(\Rightarrow\)n chia hết cho n + 1

\(\Rightarrow\)n = 0 

12-8=4 thi lay5-1=4 

4×4=16 . 16 +12=28 ×8+5 là ra 

Okkkkkkkk

y+y:2+y:4=35

y+y x \(\frac{1}{2}\)+y x \(\frac{1}{4}\)=35

y x (1+\(\frac{1}{2}\)+\(\frac{1}{4}\))=35

y x \(\frac{7}{4}\)=35

y=35:\(\frac{7}{4}\)

y=20

y + y : 2 + y : 4 = 35

y + y x 1/2 + y x 1/4 = 35

y x ( 1 + 1/2 + 1/4 ) = 35

y x 7/4 = 35

y = 35 : 7/4

y = 20

y + y : 2 + y : 4 = 35

y + y x 1/2 + y x 1/4 = 35

y x (1 + 1/2 + 1/4) = 35

y x 7/4 = 35

x = 35 : 7/4

x = 20