Bài 5: Tìm số nguyên x, biết: 1) x + (-37) = 23 2) x – (-37) = 23 3) 123 – x = -63 4) 21 – (29 + x) = -12 5) (-54) + x =-32 6) x – (-27) = -42 7) -53 – x = -63 8) -13 – (x + 9) = 23 9) (x – 63) + 47 =...

Bài 5: 1) x + (-37) = 23 x - 37 = 23 x = 23 + 37 x = 60 2) x – (-37) = 23 x + 37 = 23 x = 23 - 37 x = -14 3) 123 – x = -63 123 - x = -63 x = 123 + 63 x = 186 4) 21 – (29 + x) = -12 21 - 29 - x = -12 -8 - x = -12 x = -12 + 8 x = -4 5) (-54) + x = -32 -54 + x = -32 x = -32 + 54 x = 22 6) x – (-27) = -42 x + 27 = -42 x = -42 - 27 x = -69 7) -53 – x = -63 -53 - x = -63 x = -63 + 53 x = -10 8) -13 – (x + 9) = 23 -13 - x - 9 = 23 -22 - x = 23 x = 23 + 22 x = 45 9) (x – 63) + 47 = -83 x - 63 + 47 = -83 x - 16 = -83 x = -83 + 16 x = -67 10) (x – 65) – 8 = -23 x - 65 - 8 = -23 x - 73 = -23 x = -23 + 73 x = 50 11) (x + 21) (65 – x) = 0 Ta có hai trường hợp: - Nếu x + 21 = 0 thì x = -21 - Nếu 65 - x = 0 thì x = 65 12) (x - 45):(-6) + 54 = (-30) (x - 45):(-6) = -30 - 54 (x - 45):(-6) = -84 x - 45 = -84 × (-6) x - 45 = 504 x = 504 + 45 x = 549