60 u²
1) Given that point (3,-5) is reflected across the x-axis:
(Reflection across the x-axis follows this rule)
(x,y) --------------------------> (x, -y)
(-3,5) --------------------------> (-3, -5)
2) Reflect it across the y-axis
(x, y) -----------------> (-x, y)
(-3,5) -----------------> (3,5)
3) Another reflection just like in the graph above
(x, y) -------------->(x, -y)
(
A''''(-3,5)
4) The area of the rectangle is given by S= w*l
A = w * l
w =3 - (-3) = 6
l =5 -(-5) = 10
A = 6 * 10
A = 60 u²