20. Find an equation for the plane parallel to 3x − 3y + 2x = 5 and through the point (4, 3, 5). 21. Find an equation for the plane orthogonal to the line x(t) = (2 + t, 3 − 2t, 1 − t) and through (1, 0, −3).

20. I suppose you meant to write ? This plane has normal vector (3, -3, 2), so the equation of the plane parallel to this one that goes through (4, 3, 5) is

21. The tangent to is parallel to the normal vector to the plane, so we can simply use it as the normal vector. This tangent vector is

Then the plane has equation

to find the perimeter of the rectangle this is the expression:

x-9+x-9+3x-4+3x-4=138

if we simplify it:

8x-26=138

remember, 138 is what it all adds up to

the length is 11.5cm

the width is 57.5cm

the area is 661.25cm^2

the answers might not be correct use at own risk