—About an hour every day.
A:How long; spend
B:How long; cost
C:How often; spend
D:How often; take
(1)解方程:12x(x﹣1)﹣(x﹣1)=0.
(2)已知抛物线y=﹣2x2+8x﹣6,请用配方法把它化成y=a(x﹣h)2+k的形式,并指出此抛物线的顶点坐标和对称轴.
下列式子:x2,1a+4,3ab27,abc,−5x,0中,整式的个数是( )