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folosind formulele de calcul prescurtat,dupa efectuarea calculului: (2x-+3)(2x-3)-3(x-2)la patrat-(x+6) la patrat va rog ajutati-ma

Răspuns :

(2x+3)(2x-3)-3(x-2)²-(x+6)²=
=4x
²-9-3x²+12x-12-x²-12x-36=
=-57

[tex](2x+3)(2x-3)-3 (x-2)^{2}- (x+6)^{2} = \\=(2x)^{2} - 3^{2}-3( x^{2} -2*x*2+ 2^{2} )-( x^{2} +2*x*6+ 6^{2} )=\\=4 x^{2} -9-3( x^{2} -4x+4)-( x^{2} +12x+36)=4 x^{2} -9-3 x^{2} +\\+12x-12- x^{2} -12x-36=-57 [/tex]