We go to school ____ ____.
若a5=b7=c8,且3a-2b+c=3,则2a+4b-3c的值是( )
二次函数y=ax2+bx+c上有A(x1,y1)、B(x2,y2),x1≠x2,y1=y2,当x=x1+x2时,y=( )