题目按要求计算:(1)(1)(1)计算:∣−2∣−18+(3+2)(3−2)|-\sqrt{2}|-\sqrt{18}+(\sqrt{3}+\sqrt{2})(\sqrt{3}-\sqrt{2})∣−2∣−18+(3+2)(3−2)；(2)(2)(2)解二元一次方程组:{x+2y=4①3x+4y=16②\left\{\begin{array}{l}{x+2y=4①}\\{3x+4y=16②}\end{array}\right.{x+2y=4①3x+4y=16②.知识点：解一元一次不等式章节：方程与不等式 / 不等式与不等式组
