A rectangular floor 18 feet by 10 feet is to be completely covered with carpeting that costs x dollars per square yarD.In terms of x, how many dollars will the carpeting cost? (1 yard = 3 feet) E.540x
A.20x B.28x C.60x D.180x
【参考答案】
A 解析：一长为18英尺，宽为10英尺的长方形地板要全部铺上每平方码x美元的地毯。以x为单位，地毯总共需花多少钱......