分解因式
4(a+b)(a+b)-9(a-b)(a-b)
分解因式 4(a+b)(a+b)-9(a-b)(a-b)
2006-10-15 6:18 am
回答 (5)
2006-10-15 6:40 am
✔ 最佳答案
4(a+b)(a+b)-9(a-b)(a-b) = [2(a+b)]^2 - [3(a-b)]^2
= [2(a+b)+3(a-b)][2(a+b)-3(a-b)]
= (2a+2b + 3a- 3b) (2a+2b -3a +3b)
= (5a-b) (5b-a)
2006-10-15 6:14 pm
4(a+b)(a+b)-9(a-b)(a-b)
= [2(a+b)]^2 - [3(a-b)]^2
= [2(a+b)+3(a-b)][2(a+b)-3(a-b)]
= (2a+2b + 3a- 3b) (2a+2b -3a +3b)
= (5a-b) (5b-a)
= [2(a+b)]^2 - [3(a-b)]^2
= [2(a+b)+3(a-b)][2(a+b)-3(a-b)]
= (2a+2b + 3a- 3b) (2a+2b -3a +3b)
= (5a-b) (5b-a)
2006-10-15 7:58 am
4(a+b)(a+b)-9(a-b)(a-b)
=2^2(a+b)^2-3^2(a-b)^2
=[2(a+b)]^2-[3(a-b)]^2
=(2a+2b+3a-3b)(2a+2b-3a+3b)
=(5a-b)(5b-a)
=2^2(a+b)^2-3^2(a-b)^2
=[2(a+b)]^2-[3(a-b)]^2
=(2a+2b+3a-3b)(2a+2b-3a+3b)
=(5a-b)(5b-a)
2006-10-15 7:58 am
A^2-B^2=(A+B)(A-B)
4(a+b)(a+b)-9(a-b)(a-b)
=[4(a+b)^2]-[9(a-b)^2]
=[2^2*(a+b)^2]-[3^2*(a-b)^2]
=[2(a+b)]^2-[3(a-b)]^2
={[2(a+b)]+[3(a-b)]}*{[2(a+b)]-[3(a-b)]}
={2a+2b+[3a-3b]}*{2a+2b-[3a-3b]}
={2a+2b+3a-3b}*{2a+2b-3a+3b}
={5a-b}{-a+5b}
=-5a^2+26b-5b^2
4(a+b)(a+b)-9(a-b)(a-b)
=[4(a+b)^2]-[9(a-b)^2]
=[2^2*(a+b)^2]-[3^2*(a-b)^2]
=[2(a+b)]^2-[3(a-b)]^2
={[2(a+b)]+[3(a-b)]}*{[2(a+b)]-[3(a-b)]}
={2a+2b+[3a-3b]}*{2a+2b-[3a-3b]}
={2a+2b+3a-3b}*{2a+2b-3a+3b}
={5a-b}{-a+5b}
=-5a^2+26b-5b^2
參考: me
2006-10-15 6:48 am
4(a+b)(a+b)-9(a-b)(a-b)
=4(a^2+b^2)-9(a^2+b^2)
=4a^2+4b^2-9a^2-9b^2
=4a^2-9a^2+4b^2-9b^2
=-5a^2-5b^2
2006-10-14 22:59:09 補充：
咦?死, 計錯數, sori 4(a b)(a b)-9(a-b)(a-b) =[4(a b)(a b)]-[9(a-b)(a-b)]=[4(a b)^2]-[9(a-b)^2]=[(a b)^2](4-9)
2006-10-14 23:09:45 補充：
點解出唔到個「加」號既~!?sori 4(a加b)(a加b)-9(a-b)(a-b) =[4(a加b)(a加b)]-[9(a-b)(a-b)]=[4(a加b)^2]-[9(a-b)^2]=[(a加b)^2](4-9)=[4(a加b)^2]-[9(a加b)^2]
=4(a^2+b^2)-9(a^2+b^2)
=4a^2+4b^2-9a^2-9b^2
=4a^2-9a^2+4b^2-9b^2
=-5a^2-5b^2
2006-10-14 22:59:09 補充：
咦?死, 計錯數, sori 4(a b)(a b)-9(a-b)(a-b) =[4(a b)(a b)]-[9(a-b)(a-b)]=[4(a b)^2]-[9(a-b)^2]=[(a b)^2](4-9)
2006-10-14 23:09:45 補充：
點解出唔到個「加」號既~!?sori 4(a加b)(a加b)-9(a-b)(a-b) =[4(a加b)(a加b)]-[9(a-b)(a-b)]=[4(a加b)^2]-[9(a-b)^2]=[(a加b)^2](4-9)=[4(a加b)^2]-[9(a加b)^2]
收錄日期: 2021-04-13 13:42:22
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061014000051KK06148