✔ 最佳答案
你好～～～
以下都是本人的一些意見而已～
1a) 3(x - 2) = 3x - 6
b) 2x(1 + x^2) = 2x + 2x^3 = 2x^3 + 2x
c) -2(a + b - c) = -2a - 2b + 2c = 2c - 2a - 2b
d) (x + 1)(x - 2) = x^2 - 2x + x - 2 = x^2 - x - 2
e) (3x + 1)(2x^2 - 5x) = (3x)(2x^2) - (3x)(5x) + 2x^2 - 5x = 6x^3 - 15x^2 + 2x^2 - 5x = 6x^3 - 13x^2 - 5x
f) (5x - y)^2 = (5x)^2 - 2(5x)(y) + y^2 = 25x^2 - 10xy + y^2
2a) 5x^2 - 2x + 4 - 2x^2 - x + 10
= 5x^2 - 2x^2 - 2x - x + 4 + 10
= 3x^2 - 3x + 14
2b) (x=4y-z)+(5x-4y+3z) [我把那個等號當作為加號看吧]
(x + 4y - z) + (5x - 4y + 3z) = x + 5x + 4y - 4y + 3z - z = 6x + 2z
2c) (2h-k)-(5h-9k) = 2h - 5h - k + 9k = -3h + 8k = 8k - 3h
2d) 6(a+b)-4(a-b)
= 6a + 6b - 4a + 4b
= 6a - 4a + 6b + 4b
= 2a + 10b
2e) (70+2x)-(x-37) = 70 + 37 + 2x - x = 107 + x
3) 他買入雞蛋所需的錢︰3m * n = 3mn
他賣出雞蛋所得的錢︰n(n - 5m) = n^2 - 5mn
盈餘︰n^2 - 5mn - 3mn = n^2 - 8mn
4a) 3*16^2+10*16^1+11 = 3AB(16)
b) 8*16^3+0*16^2+1*16^1+15 = 801F(16)
5a) 11101(2) = 1 * 2^2 = 4
5b︰底線……在那裏？ 6a) 1101(2) = 1 * 2^3 + 1 * 2^2 + 0 * 2^1 + 1 * 2^0 b) F99D(16) = 15 * 16^3 + 9 * 16^2 + 9 * 16^1 + 13 * 16^0 7a) 10(2) = 1 * 2^1 = 2 b) 110(2) = 1 * 2^2 + 1 * 2^1 = 4 + 2 = 6 8a) 0(10) = 0(2) b) 35(10) = 32 + 2 + 1 = 1 * 2^5 + 0 * 2^4 + 0 * 2^3 + 0 * 2^2 + 1 * 2^1 + 1 * 2^0 = 100011(2) 9a) 4E68(16) = 4 * 16^3 + 14 * 16^2 + 6 * 16^1 + 8 * 16^0 = 20072(10) b) 4C59(16) = 4 * 16^3 + 12 * 16^2 + 5 * 16^1 + 9 * 16^0 = 19545(10)
希望可以幫到你～～～～～
2011-08-25 14:38:20 補充：
7a 那道題目...二進制好像沒有 9，只有 1 與 0 而已……
應該是 8a 吧？？
8a) 9(10) = 8 + 1 = 1 * 2^3 + 0 * 2^2 + 0 * 2^1 + 1 * 2^0 = 1001(2)
5b) 23A7(16)
3 -> 3 * 16^2 = 768
