Two adjacent angles have a sum of 100° the angles have measures <1= 20° and <2=(3x+15) degrees which equation can be used to solve X?

3x+115=20
3x-20=100
3x-100=20
3x+35=100

The equation that can be used to solve for x is 3x + 15 + 20 = 100.

A:3x+115=20

B:3x-20=100
C:3x-100=20
D:3x+35=100

The correct equation that can be used to solve for x is D: 3x + 35 = 100.