Hello.
I was trying to typeset the following system of equations:
I used the following code in order to do it:
\begin{equation*}
\left\{
\begin{alignedat}{9}
& b_{1,1} x_2 &&{} + {}&& b_{1,2} x_2 &&{} + {}&& \cdots &&{} + {}&& b_{1,9} x_9 &&{} = {}&& c_1 \\
& b_{2,1} x_2 &&{} + {}&& b_{2,2} x_2 &&{} + {}&& \cdots &&{} + {}&& b_{2,9} x_9 &&{} = {}&& c_2 \\
&&& \: \: \vdots &&&& \: \: \vdots &&&& \: \: \vdots &&&& \:\: \vdots \\
& b_{9,1} x_2 &&{} + {}&& b_{9,2} x_2 &&{} + {}&& \cdots &&{} + {}&& b_{9,9} x_9 &&{} = {}&& c_9
\end{alignedat}
\right.
\end{equation*}
Now, I have 2 questions:
- Is there a more natural way to add the spacing between the columns?
- Why does
{} + {}
work (that is, adds the spaces around the+
sign)? I got it by accident (desperate times call for desperate measures), but have no idea how/why it works.
\quad
or\qquad
for add space?{}+{}
, a plus sign can indicate an operation, as ina + b
or it can be a sign as in+b
. The spacing is different for these two cases. Adding the braces indicates to TeX that the plus should be taken as within an operation.