Calculezi E(x) folosind formulele:
[tex] (a+b)^2 =a^2 +2ab +b^2 \\ (a-b)^2 =a^2 -2ab+b^2 [/tex]
[tex] E(x) =(x\sqrt{2} +4)^2 -(x\sqrt{2} +3)(x\sqrt{2} +5) +(x\sqrt{3} +1)^2 +3x(1-2\sqrt{3}) +3 \\ = 2x^2 +8\sqrt{2} x +16 -(2x^2 +8\sqrt{2} x +15) +3x^2 _2\sqrt{3} x +1 +3x -6\sqrt{3} x +3 \\ = 2x^2 +8\sqrt{2} x +16 -2x^2 -8\sqrt{2} x -15 +3x^2 -4\sqrt{3} x +4+3x \\ = 1+3x^2 -4\sqrt{3} x +3x +4 \\ = \tt 3x^2 +(3-4\sqrt{3} ) x +5 [/tex]
