Help? I’m not really understanding this.

Answer:
x = 109
Step-by-step explanation:
[tex](x + 12) \degree + 59 \degree = 180 \degree \\ (sum \: of \: exterior \: angles \: on \: same \: side \: \\ of \: transversal) \\ (x + 71) \degree = 180 \degree \\ x + 71 = 180 \\ x = 180 - 71 \\ \purple{ \bold{ x = 109}}[/tex]