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Mathematics
Mathematics
Problem
Find the measure of the angle between the lines
x
+
y
+
7
=
0
x + y + 7 = 0
x
+
y
+
7
=
0
and
x
−
y
+
1
=
0
x - y + 1 = 0
x
−
y
+
1
=
0
.
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