Question

[Nguyễn Thị Phương Thảo]

20:x+30:x=4:8:x+50và1/2

Answer 1

[Vũ Đức Thịnh]

\(20:x+30:x=4:8:x+50\dfrac{1}{2}\)

\(20\times\dfrac{1}{x}+30\times\dfrac{1}{x}=\dfrac{1}{2}:x+\dfrac{101}{2}\)

\(\left(20+30\right)\times\dfrac{1}{x}=\dfrac{1}{2}\times\dfrac{1}{x}+\dfrac{101}{2}\)

\(50\times\dfrac{1}{x}-\dfrac{1}{2}\times\dfrac{1}{x}=\dfrac{101}{2}\)

\(\left(50-\dfrac{1}{2}\right)\times\dfrac{1}{x}=\dfrac{101}{2}\)

\(\dfrac{99}{2}\times\dfrac{1}{x}=\dfrac{101}{2}\)

\(\dfrac{1}{x}=\dfrac{101}{2}:\dfrac{99}{2}=\dfrac{101}{99}\)

\(x=1:\dfrac{101}{99}=\dfrac{99}{101}\)

Answer 2

[Nguyễn Thị Phương Thảo]

dấu cộng trước 50 là dấu bằng