... Bµi 61 / tr 87 (SGK) T×m sè nguyªn x, biÕt: a) 7 – x = 8 – ( - 7) b) x – 8 = ( -3 ) - 8 §¸p ¸n 7 - x = 8 + 7 - x = 8 + 7 – 7 - x = 8 x = - 8 x = ( - 3 ) – 8 + 8 x = - 3 Bµi 63 / tr 87 (SGK) T×m ... sai, gi¶i thÝch ? STT C©u §óng Sai 1 x - 45 = - 12 x = - 12 + 45 2 x -12 = 9 - 7 x = 9 - 7 -12 3 2 - x = 17 - 5 - x = 17 - 5 - 2 4 5 x = - 8– x = - 8 - 5 x x x x ... §¸p ¸n Theo bµi ra ta cã : 3 + ( - 2 ) + x = 5 3 – 2 + x = 5 x = 5 – 3 + 2 x = 4 Bµi 62 / tr 87 (SGK) T×m sè nguyªn a, biÕt : a) = 2 b) a 2 0a + = §¸p ¸n a = 2 hoÆc a = - 2 a + 2 = 0 a = 0 –...