數學升中預習唔識做！！！急！！仲有１日炸！！1５點!!

要知道,正(數)正得正,正負(數得負,負正得負,負負得正
例如(-8)+(-5)=(-8)-5= -13
又例如(-3)(-9)=27 (由於負負得正)

兩個有向數相加及相減的法則
(-8)+(-5)=__-13____ (+9)+(-2)=___7___ (+7)-(+12)=___-5___
(-5)-(-6)=___1___ (+5)+(-7)-10=__-12____ (+5)+(-7)+(-10)=___-12___
(-6)-(-8)+(+4)=__6____ (-3)+(-4)-(-7)=___0___ (+4)-(-9)+(+5)=_____18_

兩個有向數相乘的法則
(+2)(+7)=___14___ (-3)(-9)=____27__ (-10)(+7)=____-70__
(+5)(-3)=____-15__ (+2)(+13)(+4)=__104____ (-3)(-7)(-9)=___-189___
(-3)(+12)(-5)=___180___ (+4)(+17)(-3)=___-204___

兩個有向數相除的法則
(+144)÷(+12)=__12____ (-18)÷(-9)=___2___
(-169)÷(+13)=__-13____ (+196)÷(-14)=___-14___

兩個有向數相加及相減的法則
(-8)+(-5)
= -8-5
= -13
(+9)+(-2)
= 9-2
=-7
(+7)-(+12)
=7-12
=-5
(-5)-(-6)
=-5+6
=-1
(+5)+(-7)-10
=5-7-10
=-2-10
=-12
(+5)+(-7)+(-10)
= 5-7-10
=-2-10
=-8
(-6)-(-8)+(+4)
=-6+8+4
=2+4
=6
(-3)+(-4)-(-7)
=-3-4+7
=-7+7
=0
(+4)-(-9)+(+5)
=4+9+5
=13+5
18
兩個有向數相乘的法則
(+2)(+7)
=2×14
=28
(-3)(-9)
=+3×9
=27
(-10)(+7)
=-10×7
=-70
(+5)(-3)
=-5×3
=-15
(+2)(+13)(+4)
=2×13×4
=26×4
=104
(-3)(-7)(-9)
=-3×7×9
=-21×9
=189
(-3)(+12)(-5)
=3×12×5
=36×5
=180
(+4)(+17)(-3)
=-4×17×3
=68×3
=204
兩個有向數相除的法則
(+144)÷(+12)
=144÷12
=12
(-18)÷(-9)
=18÷9
=2
(-169)÷(+13)
=-169÷13
=-13
(+196)÷(-14)
=-196÷14
=-14
希望幫到你:)

(-8)+(-5)=-13
(+9)+(-2)=7
(+7)-(+12)=-5
(-5)-(-6)=1
(+5)+(-7)-10=-12
(+5)+(-7)+(-10)=-12
(-6)-(-8)+(+4)=6
(-3)+(-4)-(-7)=0
(+4)-(-9)+(+5)=18
(+2)(+7)=14
(-3)(-9)=27
(-10)(+7)=-70
(+5)(-3)=-15
(+2)(+13)(+4)=104
(-3)(-7)(-9)=-189
(-3)(+12)(-5)=180
(+4)(+17)(-3)=-204
(+144)÷(+12)=12
(-18)÷(-9)=2
(-169)÷(+13)=-13
(+196)÷(-14)=-14

正正得正
負負得正
正負得負
負正得負