What are good programs for writing expressions?

Question

By writing expressions, I mean intermediate expressions to "show your work," such as the ones in the below image. LaTex would seem like overkill for such problems.

Answer 1

I still think LaTeX is the way to go. Once you start having to write several mathematical expressions, any kind of mouse-driven system for specifying them is going to become very frustrating. LaTeX is extremely efficient for doing exactly what you want to do.

\begin{align*}
        c_1x + a     &= c_2 x + b \\
        c_1x + a - a &= c_2x + b - a\\ 
        c_1x         &= c_2x + b - a \\
        c_1x - c_2 x &= c_2x + b - a - c_2 x \\
        c_1x - c_2 x &= b - a \\
        x            &= \frac{b-a}{c_1 - c_2}
    \end{align*}

\begin{align*} c_1x + a &= c_2 x + b \\ c_1x + a - a &= c_2x + b - a\\ c_1x &= c_2x + b - a \\ c_1x - c_2 x &= c_2x + b - a - c_2 x \\ c_1x - c_2 x &= b - a \\ x &= \frac{b-a}{c_1-c_2} \end{align*}

See Getting started with LaTeX for some pointers.