2x(4x+5)=-3?
回答 (3)
2018-06-25 11:00 pm
2x(4x + 5) = -3
8x² + 10x = -3
8x² + 10x + 3 = 0
(2x + 1)(4x + 3) = 0
x = -1/2 or x = -3/4
8x² + 10x = -3
8x² + 10x + 3 = 0
(2x + 1)(4x + 3) = 0
x = -1/2 or x = -3/4
2018-06-25 11:16 pm
2x(4x+5)=_3
8x²+10x+3=0
Hence x= [-10+/- √{(10)²-4×8×3}}/(2×8)= [-10+/- √{100-96}}/(16)
=[-10+/- √{4}/(16)= [-10+/- 2]/(16)= [-5+/- 1}]/8
Hence x= -1/2 and x= -3/4
8x²+10x+3=0
Hence x= [-10+/- √{(10)²-4×8×3}}/(2×8)= [-10+/- √{100-96}}/(16)
=[-10+/- √{4}/(16)= [-10+/- 2]/(16)= [-5+/- 1}]/8
Hence x= -1/2 and x= -3/4
2018-06-25 10:51 pm
2x(4x + 5) = -3
8x^2 + 10x + 3 = 0
8x^2 + 4x + 6x + 3 = 0
4x(2x + 1) + 3(2x + 1)
(4x + 3)(2x + 1) = 0
Solutions:
x = -3/4
x = -1/2
8x^2 + 10x + 3 = 0
8x^2 + 4x + 6x + 3 = 0
4x(2x + 1) + 3(2x + 1)
(4x + 3)(2x + 1) = 0
Solutions:
x = -3/4
x = -1/2
收錄日期: 2021-05-01 22:26:53
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20180625144521AAKVzYO