okay i got a little conflict with a friend, it's about some simple factor thing ( don't know how to call it correctly in English):
(3x - 2/5)² - 16/25 =
okay, i have my version he has his, and i want to see which one is right.
(3x - 2/5)² - 16/25 =
okay, i have my version he has his, and i want to see which one is right.
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We have the difference of 2 squares
a^2 = (3x - 2/5)^2
a = (3x - 2/5)
b^2 = 16/25
b = 4/5
a^2 - b^2 =>
(a - b) * (a + b) =>
(3x - 2/5 - 4/5) * (3x - 2/5 + 4/5) =>
(3x - 6/5) * (3x + 2/5) =>
3 * (x - 2/5) * (3x + 2/5)
a^2 = (3x - 2/5)^2
a = (3x - 2/5)
b^2 = 16/25
b = 4/5
a^2 - b^2 =>
(a - b) * (a + b) =>
(3x - 2/5 - 4/5) * (3x - 2/5 + 4/5) =>
(3x - 6/5) * (3x + 2/5) =>
3 * (x - 2/5) * (3x + 2/5)
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16/15 = (4/5)²
So you have differences of the two squares.
(3x - 2/5)² - (4/5)²
= [3x - (2/5) - (4/5)][3x - (2/5) + (4/5)]
= (3x - 6/5)(3x + 2/5)
So you have differences of the two squares.
(3x - 2/5)² - (4/5)²
= [3x - (2/5) - (4/5)][3x - (2/5) + (4/5)]
= (3x - 6/5)(3x + 2/5)
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Difference of squares => a^2 - b^2 = (a - b)(a + b)
(3x - 2/5 - 4/5)(3x - 2/5 + 4/5)
= (3x - 6/5)(3x + 2/5)
(3x - 2/5 - 4/5)(3x - 2/5 + 4/5)
= (3x - 6/5)(3x + 2/5)
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factor((3*x - 2/5)^2 - 16/25) = (3/25*(15*x + 2))*(5*x - 2)