F3 MATHS(10點)

1. 5^3 X 15^-2 ÷(-5^ -2)
= 125 X (1/225) X - 25
= -125X25 / 225
= - 125/9

2. (3^-2×45^ 0)÷12^-2
= (1/9 X 1) ÷ 1/144
= 1/9 X 144
= 16

3. 7^2 - 7^-13÷7^-14
= 7^2 - [ 7^ ( -13+14)]
=7^2 - 7^1
=49-7
=42

4. (-4a^-1b-^1)^-1
= - 1/4 a^1 b^1
= - ab/4

5. (x^3y^-3)^-1/x^0y^-2
= x^ -3-0 y^3-(-2)
=x^-3 y^5
=y^5/x^3

6. (3m^2/-n^0)^-4
= (3m^2/ -1)^ -4
= ( -1/ 3m^2)^4
= 1/81m^8

7.a^-1b^9/a^0b^7
= a^(-1-0) b^(9-7)
=a^ -1 b^2
=b^2/ a

8. -2^4x^-6/2^2x^3
= -2^ (4-2) x^(-6-3)
= -2^2 x^ -9
= -4/ x^9

9. (x^2y)^4(y^-3)
= x^8 y^4-3
=x^8 y

第9條係咪打錯左
應該係 (x^2y)^ -4 (y^-3)
= x^ -8 y^(-4-3)
= 1/ x^8 y^7

1) 5^3×15^-2÷(-5^-2)
=5^3 x 3^-2 x 5^-2 / -5^-2
=5^3 / - 3^2
= - 125/9

2) (3^-2×45^ 0)÷12^-2
=3^-2 / 3^-2 x 4^-2
=1 / 4^-2
= 16

3) 7^2 - 7^-13÷7^-14
=7^2 - 7
=49 - 7
=42

4) (-4a^-1b-^1)^-1
=1/-4 x a x b
=ab /-4

5) (x^3y^-3)^-1/x^0y^-2
=x^-3 * y^3 / y^-2
= y^5/x^

6) (3m^2/-n^0)^-4
= 3^-4 m^-8
= 1/81m^

7) a^-1b^9/a^0b^7
=a^-1 b^2
= b^2/a

8) -2^4x^-6/2^2x^
=-2^2 x^-9
= -4 / x^9

9) 唔知~ 你出錯~~