1. For the expression a(x^2) + bx + 25, write down two possible sets of the values of a and b such that the expression is a perfect square.
2. Suggest two ways of factorizing (x^6) - (y^6)
MATH---Factorization
2008-07-11 2:08 am
回答 (2)
2008-07-11 2:26 am
✔ 最佳答案
1. For the expression to be a perfect square, delta = 0. That isb^2 - 4a(25) = 0
b^2 = 10^2(a)
b= 10sqrt(a).
So a= 1, b = 10.
a=4, b = 20
a=9 , b= 30. etc.
2. x^6 - y^6 = (x^2)^3 -(y^2)^3 = ........... Or
(x^3)^2 - (y^3)^2 = .....................
2008-07-13 6:08 am
There is something missed in the 1st question.
delta = 0
b^2 - 4a(25) = 0
b^2 - 100a = 0
(b+10sqrt(a))(b-10sqrt(a))=0
b= 10sqrt(a) or -10sqrt(a).
So for a=1, b can be 10 or -10
By the way, note that 'a' need to be positive (a>0).
delta = 0
b^2 - 4a(25) = 0
b^2 - 100a = 0
(b+10sqrt(a))(b-10sqrt(a))=0
b= 10sqrt(a) or -10sqrt(a).
So for a=1, b can be 10 or -10
By the way, note that 'a' need to be positive (a>0).
收錄日期: 2021-04-13 15:48:01
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