2 câu trả lời
ta có
x/16=x/16.3=x3/48
z/61=z/61.2=z2/122
áp dụng ta có
x3/48=z2/122=y/6=x3=y-2z/48+6-122=-7/17
x/16=-7/17=x=-16
y/6=-7/17=y=42/-17
z/61=-7/17=z=-427/17
$\dfrac{x}{16}=$ $\dfrac{y}{6}=$ $\dfrac{z}{61}$ $\text{và 3x + y - 2z = 28}$ $\\$ $\text{Áp dụng tính chất dãy tỉ số bằng nhau, ta có:}$ $\\$ $\dfrac{x}{16}=$ $\dfrac{y}{6}=$ $\dfrac{z}{61}=$ $\dfrac{3x + y-2z}{3.16 + 6 - 2.61}=$ $\dfrac{28}{-68}=$ $\dfrac{-7}{17}$ $\\$ $+$ $\dfrac{x}{16}=$ $+$ $\dfrac{x}{16}=$ $\dfrac{-7}{17}⇒x=$ $\dfrac{16.(-7)}{17}=$ $\dfrac{-112}{17}$ $\\$ $+$ $\dfrac{y}{6}=$ $\dfrac{-7}{17}⇒y=$ $\dfrac{(-7).6}{17}=$ $\dfrac{-42}{17}$ $\\$ $+$ $\dfrac{z}{61}=$ $\dfrac{-7}{17}⇒z=$ $\dfrac{(-7).61}{17}=$ $\dfrac{-427}{17}$ $\\$ $\underline{KL:}$ $\text{x = $\dfrac{-112}{17}$; y = $\dfrac{-42}{17}$; z = $\dfrac{-427}{17}$}$
Câu hỏi trong lớp
Xem thêm
