#23
var('x y')
def f(x,y): return 1+y
gr = plot3d(f(x,y), (x,-5,5), (y,-5,5), axes=True, frame=True)
show(gr)

# #24
var('x y')
def f(x,y): return 2-x
gr = plot3d(f(x,y), (x,-5,5), (y,-5,5), axes=True, frame=True)
show(gr)

# #25
var('x y')
def f(x,y): return 10 - 4*x - 5*y
gr = plot3d(f(x,y), (x,-5,5), (y,-5,5), axes=True, frame=True)
show(gr)