To solve the equation 2−5(3+4)=2+7,
2
-
5
(
3
+
4
x
)
=
2
x
+
7
,
Miranda's first step was to write 2−15−20=2+7
2
-
15
-
20
x
=
2
x
+
7
. Which property did Miranda use in her first step?