菠萝每千克4.20元，葡萄每千克5.4元。买4千克菠萝比买2千克葡萄多花多少元？/V.S'x'j1r6}
算式：提示,G;L'B7w:a1`/V.S'x'j1r6}
答：买4千克菠萝比买2千克葡萄多花6z,e6V元。/V.S'x'j1r6}