Solve
Equations
Linear systems, a nonlinear system, and a single irrational. 5 examples.
An unknown is a name the sheet has not already computed. = asks for a value. := sets the starting value, and the solver may move it to satisfy the equations. The right-hand side of := has to be a number the sheet can already compute. y := x is rejected. An inequality such as x > 0 is a constraint, not a value of its own, and it does not by itself choose a number.
Keep the positive root
x is the positive square root. The inequality is the constraint. It is not a boolean you can store.
Classic linear system
Two equations, two unknowns.
3×3 linear system
Three equations.
Nonlinear, with guesses
The guesses are the := lines.
Golden ratio
One equation.