cho x>y thoa man x/3 - y/7= -189 khi do x+y =
cho x,y thoa man :x-2/2=y-3/3 va x+y=10 khi do xy=
áp dụng tc dãy tc = nhau ta có:
x-2/2=y-3/3=x-2+y-3/2+3=x+y-2-3/5=10-5/5=5/5=1
=>x-2/2=1=>x-2=2=>x=4
=>y-3/3=1=>y-3=3=>y=6
vậy x.y=4.6=24
\(\frac{x-2}{2}=\frac{y-3}{3}=\frac{x-2+y-3}{2+3}=\frac{x+y-5}{5}=\frac{10-5}{5}=1\)
=> x- 2=2 ; y-3=3
=> x = 4 ; y=6
=> xy = 24
cho x,y thoa man x/3 = y/5 va x+y=16 khi do x^2+y^2=........
Áp dụng tính chất dãy tỉ số bằng nhau ta có:
x/3 = y/5 = x+y/3+5 = 16/8 = 2
=> x = 6 ; y = 10
x2 + y2 = 36 + 100 = 136
cho x,y,z thoa man x/2=2y/3=3z/4 va x-y=15. khi do x-y-z la
x/2=2y/3=3z/4=k,x=2k,y=3k:2,z=4k:3 ta có 2k-3k:2=15=1k:2=15;k=15.2=30;x=2.30=60;y=3.30:2=45,z=4.30:=40_x-y-z=-25
cho 3 so x;y;z thoa man 3x =2y ; 7y=5z va x+z-y =32 . khi do x+y-z= ?
cho hai so tu nhien x va y thoa man 2^x+1*3^y=12^x khi do x+y=
ai giup dau tien cho 2 like
\(2^{x+1}.3^y=12^x=>2^{x+1}.3^y=2^{2x}.3^x=>\frac{2^{2x}}{2^{x+1}}=\frac{3^y}{3^x}=>2^{x-1}=3^{y-x}=>x-1=y-x=0\)
=>x=y=1
vậy x+y=2
Cho hai so tu nhien x va y thoa man 2x+1.3y=12x
khi do x+y= ?
Biet x;y;z thoa man x-1/2=y-2/3=x-3/4 va x-2y+3x=-10. Khi do x+y+z =?
cho cac so x,y,z thoa man( x-1)/2=(y-2)/3=(z-3)/4 va 2x +3y-z=95 khi do x+y+z =
ai nhanh minh tich
biet x;y;z thoa man: (x-1)/2 = (y-2)/3 = (z-3)/4 va x-2y+3z = -10
khi do x+y+z = ?
suy ra x-1/2+1=y-2/3+1=z-3/4+1 suy ra x+1/2=y+1/3=z+1/4 = K Ta có x=2K-1;y=3K-1;z=4k-1 mà x-2y+3z =-10