Răspuns:
Explicație pas cu pas:
(a + b)^2 = a^2 + 2*a*b + b^2
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(x + 1/2)^2 = x^2 + 2*x*1/2 + 1/4 = x^2 + x + 1/4
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(2x + 1/2)^2 = 4x^2 + 2*2x*1/2 + 1/4 = 4x^2 + 2x + 1/4
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(3x + 1/3)^2 = 9x^2 + 2*3x*1/3 + 1/9 = 9x^2 + 2x + 1/9
