Question

x/2=y/3=x/5  và xyz=810

Answer 1

Đặt \(\frac{x}{2}=\frac{y}{3}=\frac{z}{5}=k\)

\(\Rightarrow x=2k;y=3k;z=5k\)

\(\Rightarrow xyz=2k.3k.5k\)

\(\Rightarrow30k^3=810\)

\(\Rightarrow k^3=27\)

\(\Rightarrow k=\pm3\)

Khi k = 3 thì x = 3.2 = 6 ; y = 3.3 = 9; z = 3.5 = 15

Khi k = -3 thì x = (-3).2 = -6; y = (-3).3 = -9; z = (-3).5 = -15

Answer 2

\(\frac{x}{2}=\frac{y}{3}=\frac{z}{5}\) và \(xyz=810\)

ĐẶT \(\frac{x}{2}=\frac{y}{3}=\frac{z}{5}=k\)

\(\Rightarrow x=2k;y=3k,z=5k\)

TA CÓ: xyz = 2k . 3k . 5k = 810

                  => ( 2.3.5 ) .k.k.k = 810

                  => 30 k³ = 810

                  => k³ = 810 : 30 = 27

=> k = 3

=> x=2k = 2.3 = 6

=>y=3k = 3.3=9

=> z=5k = 5.3 = 15

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