Question

a,x/4=y/2=z/3 và 3x-2y+4z=20

b,x/2=y/6 và x-y=10

c, x/2=y/3=z/4 và x.y.z=24

lm giúp mk vs nha. mk đang cần gấp. mk tick cho. cảm ơn nhìu

Answer 1

câu b:

\(\dfrac{x}{2}=\dfrac{y}{6}\\ \dfrac{x}{2}=\dfrac{y}{6}=\dfrac{x-y}{2-6}=\dfrac{10}{-4}=\dfrac{5}{-2}\\ x=\dfrac{5}{-2}.2=\dfrac{10}{-2}=-5\\ y=\dfrac{5}{-2}.6=-15\)

Answer 2

câu a:

\(\dfrac{x}{4}=\dfrac{y}{2}=\dfrac{z}{3}\\ \dfrac{3x}{3.4}=\dfrac{2y}{2.2}=\dfrac{4z}{4.3}\\ \)

ta có

\(\dfrac{3x}{3.4}=\dfrac{2y}{2.2}=\dfrac{4z}{4.3}=\dfrac{3x+2y+4z}{12+4+12}=\dfrac{20}{28}=\dfrac{5}{7}\\ x=\dfrac{5}{7}:4=\dfrac{5}{28}\\ y=\dfrac{5}{7}:2=\dfrac{5}{14}\\ z=\dfrac{5}{7}:3=\dfrac{5}{21}\)

Answer 3

câu c,

ta có:

\(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{4}=k\\ x=2k;y=3k;z=4k\\ x.y.z=2k.3k.4k=24k=24\)

=>k=1

x=2.1=2

y=3.1=3

z=4.1=4