Baøi 3: Tìm x:
1/ (2x – 5) + 17 = 6
2/ 10 – 2(4 – 3x) = -4
3/ - 12 + 3(-x + 7) = -18
4/ 24 : (3x – 2) = -3
5/ -45 : 5.(-3 – 2x) = 3
Baøi 4: Tìm x
1/ x.(x + 7) = 0
2/ (x + 12).(x-3) = 0
3/ (-x + 5).(3 – x ) = 0
4/ x.(2 + x).( 7 – x) = 0
5/ (x - 1).(x +2).(-x -3) = 0
Baøi 5: Tìm
1/ Ö(10) vaø B(10)
2/ Ö(+15) vaø B(+15)
3/ Ö(-24) vaø B(-24)
4/ ÖC(12; 18)
5/ ÖC(-15; +20)
Baøi 6: Tìm x bieát
1/ 8 chia hết vaø x > 0
2/ 12 chia hết vaø x < 0
3/ -8 chia hết vaø 12 x
4/ x 4 ; x (-6) vaø -20 < x < -10
5/ x (-9) ; x (+12) vaø 20 < x < 50