3. Formul 13. Scrie, sub forma cea mai simplă, următoarele expresii algebrice: a) E(x) = (x + 2)² + (x-2)(x+2); b) E(x) = (x-3)(x+3) - (x-4)²; c) E(x) = (2x - 5)² + (x + 1)² - (x√√5 + 3)(x√√/5-3); d) E(x) = 2(x-6)² + (x-2√3)(x+2√3) - (2x - 1)²; e) E(x) = 3(x - √2)(x + √2) - (x + √2)²-(x - √√2)²; f) E(x) = (x² - 2)²-(x - 1)(x + 1)(x² + 1) + 4(x − 3)²; g) E(x) = (x + 2)(x² + 4)(x-2)-(2-x²)²; h) E(x) = (x-3)(x² +9)(x+3) - (x² + 1)(1+x)(x-1) + 8.​