已知 4x=3y,求代数式 (x-2y)2-(x-y)(x+y)-2y2的值.
计算:
(1) −12+20180−(12)−1+3√8;
(2) a2−b2a−b÷a+b2a−2b.
(1)分解因式: 3x3−27x
(2)解不等式组: {2x+1>x−1…①x−1⩽13(2x−1)…②
(1) (−2)2×|−3|−(√6)0
(2) (x+1)2−(x2−x)
解方程(组 ):
(1) 1x−2=1−x2−x−3;
(2) {2x+3y=44x+4y=42
(1) tan60°+(3−√3)−12;
(2) (2x−1)2−(x+1)(x−1).