tim x biet
x-3/x+5=5/7
tim x biet :3/[x+2][x+5]+5[x+5][x+10]+7/[x+10][x+15]=x/[x+12][x+17]
tim x,y thuoc z biet x/5=y/3=z/4 và x-z=7
tim x,y thuộc z biết x/3=y/4=z/5 và 2z+3y+5z=86
Tim x,y,z biet:
(2|x|+5)/3=(3|y|-1)/5=(3-z)/7 va 2|x|+7|y|+3z=-14
Tim x:
a,(x-3)(x+4)>0
b,|5/7. x-4| < 2/7
tim x
a ) x.( x-8) - x.(x+ 1) = 2
b) ( x + 3).5 - 7.(x+9)=0
c 4 ( x - 7) + 7.(x-2)=11
tim x biet (x^2-1)(x^2-3)(x^2-5)(x^2-7)<=0
Tim x biet
1/1*3+1/3*5+1/5*7+1/7*9+...+1/x(x+2)=16/34
Tim x VA y (x-3).(y-5)=7