(p^2 + q^2)^2 - 4p^2q^2
36x^2 - 12x - 169y^2 + 26y
Jo has 2 pieces of wire of the same length. He bends 1 piece of wire into a rectangle and the other into a square.
a. If the length and the width of the rectangle are a and b cm respectively, find the length of each side of the square in terms of a and b.
b. If the length of the rectangle is 9 cm longer than its width, find the difference between the areas of the square and rectangle
中三 Factorization!!!!!Help!!!!!!
2007-10-16 6:40 am
回答 (2)
2007-10-16 7:33 am
✔ 最佳答案
1. (p2+ q2)2 - 4p2q2 = (p2+ q2 + 2pq)(p2+ q2- 2pq)
= (p + q)2 (p - q)2
2. 36x2 - 12x - 169y2 + 26y
= (36x2 - 169y2) - (12x - 26y)
= (6x + 13y) (6x - 13y) - 2(6x - 13y)
= (6x - 13y)(6x + 13y + 2)
3a. Length of the wire = 2(a + b) cm.
So length of each side of the square = 2(a + b)/4 = (a + b)/2 cm
b. a - b = 9
a = b + 9
Area of rectangle
= (b + 9)(b) cm2
= (b2 + 9b) cm2
Area of square
= [(b + b + 9)/2 ]2 cm2
= (4b2 +72b + 81)/4 cm2
= (b2+ 18b + 81/4) cm2
Difference
= [ (b2+ 18b + 81/4) - (b2 + 9b) ] cm2
= (9b + 81/4) cm2
2007-10-18 00:53:19 補充：
Yes, that is.2. Answer is (6x - 13y)(6x ＋ 13y - 2)
2007-10-16 6:18 pm
Should the answer to Q2 be (6x-13y)(6x+13y-2) instead of (6x-13y)(6x+13y+2)?
收錄日期: 2021-04-13 13:56:13
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