bài 1 : Tìm x :
1. (81−x2).(−2x−16).(−3x+15)=0(81−x2).(−2x−16).(−3x+15)=0
bài 2: Tìm x,y thuộc Z
1, (2x−1).(4y+2)=−42(2x−1).(4y+2)=−42
2,(5x+1).(y−1)=4
bài 3:Tìm x thuộc Z
a, \(\left(x-4\right)⋮\left(x+1\right)\)
b,\(\left(2x+5\right)⋮\left(x-1\right)\)
c,\(\left(3x+2\right)⋮\left(2x-1\right)\)