1. Given two circles $\mathrm{e} O_{1}$ and $\mathrm{e} O_{2}$ with centers on the line $y=1-x$, intersecting at points $A$ and $B$, and $A(-7,9)$, then the coordinates of point $B$ are $\qquad$
1. $B(-8,8)$

Analysis: To find the symmetric point of $A(-7,9)$ with respect to $y=1-x$, let $B(p, q)$, then
$$
\left\{\begin{array} { c } 
{ q + 9 = 2 - ( p - 7 ) } \\
{ q - 9 = p + 7 }
\end{array} \Rightarrow \left\{\begin{array}{c}
p=-8 \\
q=8
\end{array}\right.\right.
$$