Question

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Answer 1

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Answer 2

Răspuns:

a,b de

Se      aaplica     formula
(a±b)²=a²±2ab+b²

a)(2x-7)²=4x²-2*2x*7+49=

4x²-28x+49

b)(3x+4)²=(3x)²+2*3x*4+4²=

9x²+24x+16

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d)(2x-y)²=(2x)²-2*2x*y+y²=

4x²-4xy+y²

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(5x-3y)²=(5x)²-2*5x*3y+(3y)²=

25x²-30xy=9y²

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e   si      f

Se    aplica     fornmula
(a-b)(a+b)=a²-b²

e)(5x-7)(5x+7)=(5x)²-7²=25x²-49

f)(6x-5y)(6x+5y)=36x²-25y²

Explicație pas cu pas: