Question

1.   x/2=x/3;y/5=z/7 và x+y+z=92

2.   x=y/2=z/3 và 4x-3y-2z=36

3.   2x=3y=5z và x+y-z=95

4.   2/3x=1/5y=5/6z và x-y+z=46

Answer 1

1.

\(\frac{x}{2}=\frac{y}{3}=>\frac{x}{10}=\frac{y}{15}\)

\(\frac{y}{5}=\frac{z}{7}=>\frac{y}{15}=\frac{z}{21}\)

=>\(\frac{x}{10}=\frac{y}{15}=\frac{z}{21}=\frac{x+y+z}{10+15+21}=\frac{92}{46}=2\)

=> x=2x10=20

y=2x15=30

z=2x21=42

Answer 2

2.

\(\frac{x}{1}=\frac{y}{2}=\frac{z}{3}=\frac{4x-3y-2z}{4-6-6}=\frac{36}{-8}=-\frac{9}{2}\)

=> x=\(-\frac{9}{2}x1=-\frac{9}{2}\)

y=\(-\frac{9}{2}x2=-9\)

z=\(-\frac{9}{2}x3=-\frac{27}{2}\)

Answer 3

3. \(2x=3y=5z\Rightarrow\frac{2x}{30}=\frac{3y}{30}=\frac{5z}{30}\Rightarrow\frac{x}{15}=\frac{y}{10}=\frac{z}{6}=\frac{x+y-z}{15+10-6}=\frac{95}{19}\)

=> x=95/19x15=....

y=95/19x10=...

z=96/19x6=...