hi i have a mock GCSE in 2 days and my mind has gone blank with these so can you explain as you answer
thanks :)
Can anyone work out the quadratic equation....: 10x^2 - 6x - 4 = 0?
2008-02-17 2:50 pm
回答 (4)
2008-02-17 2:57 pm
✔ 最佳答案
10x^2 - 6x - 4 = 0(2x - 2)(5x + 2) = 0
2x - 2 = 0
2x = 2
x = 2/2
x = 1
5x + 2 = 0
5x = -2
x = -2/5
∴ x = 1 or -2/5
2008-02-17 2:56 pm
5x² - 3x - 2 = 0
(5x + 2)(x - 1) = 0
x = - 2 / 5 , x = 1
(5x + 2)(x - 1) = 0
x = - 2 / 5 , x = 1
2008-02-17 2:55 pm
[08]
10x^2-6x-4=0
10x^2-10x+4x-4=0
10x(x-1)+4(x-1)=0
(x-1)(10x+4)=0
x=1 or -4/10
10x^2-6x-4=0
10x^2-10x+4x-4=0
10x(x-1)+4(x-1)=0
(x-1)(10x+4)=0
x=1 or -4/10
2008-02-17 2:56 pm
Ok, first start witht he formula -b+-root(b^2-4ac)
______________
2a
you should get 6+-root(36+160)
____________
20
from there the root of your sum, 36+160=196, which is 14
then you have 6+-14
____
2
your two answers for x should be 1 and -4/5 (from-8/20)
______________
2a
you should get 6+-root(36+160)
____________
20
from there the root of your sum, 36+160=196, which is 14
then you have 6+-14
____
2
your two answers for x should be 1 and -4/5 (from-8/20)
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