4x=3y
=>x/3=y/4
=>x2/9=y2/16=(x2+y2)/(9+16)=100/25=4 (dùng tính chất dãy tỉ số bằng nhau)
x2/9=4=>x2=36=>x=6 hoặc x=-6
y2/16=4=>y2=64=>y=8 hoặc y=-8
tim x,y biet
a/ x/y = 3/4 va -3x + 5y =33
b/ x2/y2 = y2/16 va x2 + y2 = 100
c/ x/4 = y/7 va x.y =112
tim x,y biet
a/ x/y = 3/4 va -3x + 5y =33
b/ x2/y2 = y2/16 va x2 + y2 = 100
tim x, y, z biet:
2/3.x=3/4.y=4/5.z va x+y-z=57
Tim x biet :
a) x-1/2=y-2/3=z-3/4 va 2/x+3/y-z
Tim x,z,y biet
x/2=y/3;y/4=z/5 va x+y-z=10
tim x,y,z biet 4/x+1=2/y-2=3/z+2 va xyz=12
Tim x,y,z biet:
x+1/ 3 = y+2/ 4 = z+3/ 5 va x+y+z= 18
Tim cac sox y z biet x-1/2=y-2/3=z-3/4 va x-2*y+3*z=14
Tim x+y+z = ? biet (x-1) /2= (y-2) /3 = (z-3) /4 va 2x+3y-z=95