-3
Solution,
Let the points be A and B
A(-3,2)------->( X1,y1)
B(-2,5)------>( x2,y2)
The three points give you three equations, which you can solve by your favorite method.
.. 0m +0n +b = 6
.. 1m +0n +b = -3
.. 0m +2n +b = 5
(m, n, b) = (-9, -1/2, 6)
so the equation of the plane can be written as
.. z = -9x -1/2y +6
_____
In standard form, this would be
.. 18x +y +2z = 12
Density = mass / volume
Mass = 25.69g and Volume = 10 mL
D = 25.69g / 10mL
Density = 2.569 g/mL