Hyperbolas- Please check my answers

**Find the vertices and locate the foci for the hyperbola whose equation is given.**

(x^2)/(81) - (y^2)/(4)=1

I got:

vertices: (-9,0), (9,0)

foci: (- squareroot 85, 0), (squareroot 85,0)

(y^2)/(100) - (x^2)/(16)=1

I got:

vertices: (0,-10), (0,10)

foci: (0, -2 squareroot 29), (0, 2 squareroot 29)

**Match the equation to the graph.**

(x^2)/(16) - (y^2)/(9)=1

I got:

http://i48.photobucket.com/albums/f2...l/f1q3g4-1.jpg

(y^2)/(16) - (x^2)/(4)=1

I got:

http://i48.photobucket.com/albums/f2...sol/f1q4g4.jpg

**Find the standard form of the equation of the hyperbola satisfying the given conditions.**

Foci: (-10, 0), (10, 0); vertices: (-5, 0), (5, 0)

I got: (x^2)/(25) - (y^2)/(75)=1

Foci: (0, -9), (0, 9); vertices: (0, -3), (0, 3)

I got: (y^2)/(9) - (x^2)/(72)=1

**Use vertices and asymptotes to graph the hyperbola. Find the equations of the asymptotes.**

(x^2)/(9) - (y^2)/(4)=1

I got:

http://i48.photobucket.com/albums/f2...ol/f1q7g11.jpg

(y^2)/(9) - (x^2)/(36)=1

I got:

http://i48.photobucket.com/albums/f2...sol/f1q8g5.jpg

**Find the location of the center, vertices, and foci for the hyperbola described by the equation.**

((x-4)^2)/(4) - ((y+4)^2)/(9)=1

I got: Center: (4, -4); Vertices: (2, -4) and (6, -4); Foci:4 -squareroot 13,-4) and (4 +squareroot 13, -4)

((y+3)^2)/(9) - ((x+4)^2)/(36)=1

I got: Center: (-4, -3); Vertices: (-4, -6) and (-4, 0); Foci: (-4, -3 - 3 squareroot 5) and (-4, -3 + 3 squareroot 5)