not entirely sure how to do it could someone explain it to me? (2x + y)^2 - 4 - '^2' being the power of 2 if its unclear :P
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by letting 2x+y = a then the equation will become a^2-4 =(a-2)(a+2) =(2x+y-2)(2x+y+2) please refer to the identity (a-b)(a+b)=a^2-b^2
Originally Posted by ryanch94 not entirely sure how to do it could someone explain it to me? (2x + y)^2 - 4 - '^2' being the power of 2 if its unclear :P Does it help if you write it as $\displaystyle \displaystyle (2x + y)^2 - 2^2$?
Originally Posted by piscoau by letting 2x+y = a then the equation will become a^2-4 =(a-2)(a+2) =(2x+y-2)(2x+y+2) please refer to the identity (a-b)(a+b)=a^2-b^2 Cheers for that! Seems quite simple now! :L
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