经过点(0,-3)和点(-2,0)的直线的斜率为( )
①
img class=kfformula src=zzximg/20190809/1565321660113443.png data-latex=\frac {2} {3}/
②
img class=kfformula src=zzximg/20190809/1565321660704793.png data-latex=\frac {3} {2}/
③
img class=kfformula src=zzximg/20190809/1565321660224474.png data-latex=-\frac {3} {2}/
④
img class=kfformula src=zzximg/20190809/1565321660377728.png data-latex=-\frac {2} {3}/