4012.sagews

solve ([6-2*(x-3)==3+x],x)

[x == 3]

solve ([-5*x > 20],x)

[[x < -4]]

solve ([5 + x < -3],x)

[[x < -8]]

def f(x): 
    return 3-2*x^2

f(100)

-19997

var ('A')
solve ([A==2+x],x)

[x == A - 2]