m<ABD + m<DBC = m<ABC
x + 38 + x + 122 = 136
add like terms (x +x) (38 + 122)
2x + 160 = 136
Subtract 160 from both sides
2x + 160 -160 = 136 -160
2x = -24
Divide both sides by 2
2x/2 = -24/2
x = -12
Check by taking -12 + 38 + -12 + 122 = 136
26 + 110= 136
136 = 136
