tim x va y:

\(\dfrac{x}{19}=\dfrac{y}{21}\) va 2x - y = 34

\(\dfrac{x}{y}=\dfrac{7}{3}\)va 5x - 2y = 87

tim x,y

Cho \(\dfrac{a}{b}=\dfrac{c}{d}\). CMR \(\dfrac{a}{2a+c}=\dfrac{b}{2b+d}\)

tìm x,y,z

\(3x=y;5y=4z\) và \(6x+7y+8z=456\)

3x = 2y ; 7y = 5z va x - y + z = 32

Tim x,y,z

Bai 1: tim x,y biet:

a, x/2= y/3 va 4x+ y= -22

b, 3x - 5y va x+3y = -28

Bai 2: tim x,y biet rang:

x/4 = y/5; y/5= z/2 va x-y+z = 98

Bai 3: tim so cay trong cua lop 7A va lop 7B. Biet rang so cay lop 7B trong nhieu hon lop 7A la 12 cay va so cay cua hai lop ti le vs 4;5

Help me!

\(\dfrac{x}{5}=\dfrac{y}{3}\)va x2 - y2 = 4

tim x va y nha cac bn!!!

\(\dfrac{x}{2}=\dfrac{y}{3}\)va xy = 54

Tim x va y

\(Cho\) \(\dfrac{a}{b}=\dfrac{c}{d}\). \(CMR:\) \(\dfrac{ab}{cd}=\dfrac{\left(a+b\right)^2}{\left(c+d\right)^2}\)

Tìm ba số x, y, z biết:

15x = 10y = 6z và z.y.z = 240