Question

\(\dfrac{x}{3}=\dfrac{y}{4}vàxy=192\)

Answer 1

Đặt x/3=y/4=k=>x=3k,y=4k

Vì xy=192=> 3k.4k=192

12k²=192

k²= 16

k=4,-4

Nếu k=4=>x=3k=3.4=12

y=4k=4.4=16

Nếu k=-4=>x=3k=3.-4=-12

y=4k=4.-4=-16

Answer 2

đặt x/3=y/4=k=>x=3k;y=4k

vì xy=192=>3k.4k=192

=>12k^2=192

=>k^2=16=>k=4;-4

nếu k=4=>x=12

=>y=16

nếu k=-4=>x=-12

=>y =-16

Answer 3

Đặt \(\dfrac{x}{3}=\dfrac{y}{4}=k\)

\(\Rightarrow x=3k;y=4k\)

Có: \(xy=3k.4k=12k^2=192\Rightarrow k^2=16\Rightarrow k=\pm4\)

Với \(k=4\Rightarrow x=3.4=12;y=4.4=16\)

Với \(k=-4\Rightarrow x=3.\left(-4\right)=-12;y=4.\left(-4\right)=16\)

Vậy \(x=\pm12;y=\pm16\)