Two adjacent angles have a sum of 100°. The angles have measures ∠1 = 20° and ∠2 = (3x + 15)°. What equation can be used to solve for x?
3x+115=20
3
+
115
=
20
3 x plus 115 is equal to 20

3x−20=100
3
−
20
=
100
3 x minus 20 is equal to 100

3x−100=20
3
−
100
=
20
3 x minus 100 is equal to 20

3x+35=100
3
+
35
=
100
3x plus 35 is equal to 100