how to easily multiply (x-2)(x-3)(x-5)?
Distributive law
do you know how to multiply numbers? like 35(56)?
easy way plz
math isnt about "easy" its about discipline
like not opening brackets mechanically
if you wanna memorize a bunch of formulas to try to sort thru, thats up to you i spose
lol there is no royal road to algebra
ok really it was "there is no royal road to geometry" but the point is the same
It doesn't matter how you do it, you will be using the following property of the real number field: distributivity of multiplication over addition
(x-2)(x-3)(x-5) ; x=10 (8)(7)(5) 56(5) = 280; 200 + 50 - 30; 2x^2 +5x -30 .. got no idea
lost him/her i am sure
indeed, but the notion is intriguing lol
x^2-5x +6 x-5 --------- x^3-5x^2+6x -5x^2+25x-30 ------------------ x^3-10x^2+31x-30 ... i wasnt even close :)
the "easy" way for me is to stack them up like numbers (they are numbers) and multiply like usual
Applying the property recursively until expansion is complete: \[\begin{eqnarray*} (x-2)(x-3)(x-5) &=& (x(x-2)-3(x-2))(x-5) \\ &=& (x^2 - 2x - 3x + 6)(x-5) \\ &=& x^2(x-5) - 2x(x-5) - 3x(x-5) + 6(x-5) \\ &=& x^3-10x^2+31x-30 \end{eqnarray*}\]
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