Câu hỏi của Trân Nguyễn

Question

5x =6y và 2x + 3y =7

Mik đg cần gấp mn làm giúp mik vs nha.

Trần Nguyễn Bảo Quyên · Accepted Answer

$5x=6y$

$\Rightarrow\dfrac{x}{6}=\dfrac{y}{5}$

$\Rightarrow\dfrac{2x}{12}=\dfrac{3y}{15}$

Áp dụng tính chất dãy tỉ số bằng nhau , ta có :

$\dfrac{2x}{12}=\dfrac{3y}{15}=\dfrac{2x+3y}{12+15}=\dfrac{7}{27}$

$\Rightarrow\dfrac{2x}{12}=\dfrac{7}{27}$$\Rightarrow2x=\dfrac{7.12}{27}=\dfrac{28}{9}$$\Rightarrow x=\dfrac{14}{9}$

$\dfrac{3y}{15}=\dfrac{7}{27}\Rightarrow3y=\dfrac{7.15}{27}=\dfrac{35}{9}$$\Rightarrow y=\dfrac{35}{27}$Câu trả lời: $5x=6y$

$\Rightarrow\dfrac{x}{6}=\dfrac{y}{5}$

$\Rightarrow\dfrac{2x}{12}=\dfrac{3y}{15}$

Áp dụng tính chất dãy tỉ số bằng nhau , ta có :

$\dfrac{2x}{12}=\dfrac{3y}{15}=\dfrac{2x+3y}{12+15}=\dfrac{7}{27}$

$\Rightarrow\dfrac{2x}{12}=\dfrac{7}{27}$$\Rightarrow2x=\dfrac{7.12}{27}=\dfrac{28}{9}$$\Rightarrow x=\dfrac{14}{9}$

$\dfrac{3y}{15}=\dfrac{7}{27}\Rightarrow3y=\dfrac{7.15}{27}=\dfrac{35}{9}$$\Rightarrow y=\dfrac{35}{27}$