Factorise this: 25x^2 + 16y^2?
回答 (9)
It can't be factorised in the set of real numbers, as the sum of two squares doesn't have any real roots (it is verified only when both x and y are equal to zero).
Not sure if you are meant to solve this with complex numbers.
(5x + 4iy)(5x - 4iy) is a possibility.
Or it could just as well be
(4y + 5ix)(4y - 5ix).
25x^2 + 16y^2
= 25x^2 - (-16y^2)
= (5x)^2 - (4iy)^2
= (5x - 4iy)(5x + 4iy)
25x^2 + 16y^2 = (5x)^2 - (4iy)^2 = (5x-4iy)(5x+4iy).
25x² + 16y²
= (5x)² + (4y)²
= (5x)² - (-4y)²
= (5x)² - (i 4y)²
= (5x + i4y) (5x - i4y)
25x^2 + 16y^2 =
(5x + 4iy)(5x - 4iy)
cannot be factored.
Did you mean 25x^2 -16y^2?
收錄日期: 2021-04-24 01:04:57
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