設 f(x)=2x平方+x-3... g(x)=3x平方-4x+1...試求..
(1) f(x)+g(x)=???
(2) f(x)-g(x)=???
(3) f(x) g(x)=???
(4)2f(x)+3g(x)=???
(5)3f(x)-2g(x)=???
2006-08-22 12:23:22 · 2 個解答 · 發問者 紅色玫瑰 1 in 教育與參考 ➔ 考試
(1)
f(x)+g(x)=
(2x^2 + x - 3) + (3x^2 - 4x + 1) = 5x^2 - 3x - 2
(2)
f(x)-g(x)=
(2x^2 + x - 3) - (3x^2 - 4x + 1) = -x^2 + 5x - 4
(3)
f(x) g(x)=
(2x^2 + x - 3) ‧ (3x^2 - 4x + 1) = 6x^4 - 5x^3 - 11x^2 + 13x -3
(4)
2f(x)+3g(x)=
2(2x^2 + x - 3) + 3(3x^2 - 4x + 1) = 13x^2 - 10x -3
(5)
3f(x)-2g(x)=
3(2x^2 + x - 3) - 2(3x^2 - 4x + 1) = 11x -11
2006-08-22 12:48:09 · answer #1 · answered by 小寶 2 · 0⤊ 0⤋
(1) 5x平方-3x-2
(2)-x平方+5x-4
(3)6x四方-5x三方－１１x平方＋１３x－３
(4)13x平方-10x-3
(5)11x-11
2006-08-22 12:43:13 · answer #2 · answered by crispypie 1 · 0⤊ 0⤋