Question 689067
Can someone please help me find the vertices and foci of the ellipse 
3x^2+7y^2=21
x^2/7+y^2/3=1
This is an equation of an ellipse with horizontal major axis.
Its standard form of equation: {{{(x-h)^2/a^2+(y-k)^2/b^2=1}}}, a>b, (h,k)=(x,y) coordinates of center.
center: 0,0)
a^2=7
a=√7
vertices: (0±a,0)=(0±√7,0)=(-√7,0) and (√7,0)
b^2=3
c^2=a^2-b^2=7-3=4
c=2
foci:  (0±c,0)=(0±2,0)=(-2,0) and (2,0)