lx-1l+lx-2l=0
l2x-6l =x-7
cho x,y thuoc Q . chung to rang:
a) lx+yl < hoac = lxl +lyl
b)lx-yl> hoac = lxl - lyl
tìm X
l x-1 l + lx -3 l <x +1
TIM X
cho ham so y=f(x)=ax+4 co do thi di qua diem A(a+1;a^3-a)
Tim A.
Voi a vua tim duoc, tinh gia tri cua x thoa màn(3x-1)=f(1-3x)
tim GTLN: -/2-3x/+1/2
tim x, y biet : x.y = -3
tim x : 0,7516 : x = (9/16)8