Question

Cho \(\frac{x}{7}=\frac{y}{13};+y=40\)Tìm x và y 

Answer 1

x/7=y/13

=>x=7m;y=13m

x+y=40

=>7m+13m=40

=>20m=40

=>m=2

=>x=2.7=14

y=40-14=26

Vậy x=14;y=26

Answer 2

\(\frac{x}{7}=\frac{y}{13}\)

=> 13x=7y

=> x=\(\frac{7}{13}y\)

Vi x+y=40

=> \(\frac{7}{13}y+y=40\)

=> \(\frac{20}{13}y=40\)

=> y=26

=> x= 40-26=14

Answer 3

\(\frac{x}{7}=\frac{y}{13}=k\Rightarrow x=7k;y=13k\)

THay x = 7k ; y = 13k vào x + y = 40 ta có:

7x + 13k = 40

20k = 40

<=> k = 40 : 20 = 2

x = 7k => x = 2 . 7 = 14

y = 13 k => y = 13 . 2 = 26

Vậy x = 14 ; y = 26  

Answer 4

phải là \(x+y=40\)chứ Bui Cam Lan Bui

\(\frac{x}{7}+\frac{y}{13}\)và \(x+y=40\)

=> \(\frac{x}{7}=\frac{y}{13}=\frac{x+y}{7+13}=\frac{40}{20}=2\)

Từ  \(\frac{x}{7}=2=>x=2.7=14\)

       \(\frac{y}{13}=2=>2.13=26\)

Vậy \(x=14;y=26\)

Tick nha