(20﹣x)(32﹣2x)=570
x=1或x=35(舍去).
故小路的宽为1米
下面事例中,由重力势能转化成动能的是(
设α、β是一元二次方程x2+2x﹣1=0的两个根,则αβ的值是( )
My friend is ________ years old. Today is his ________ birthday.