Respuesta :

supplementary means the 2 angles add up to 180 so...

124+(2x+4)=180

124+2x+4=180

124+2x+4-4=180-4

124+2x=176

124-124+2x=176-124

2x=52

2x/2=52/2

x=26
plug in and check

124+2x+4=180

124+2 (26)+4=180

124+52+4=180

176+4=180

180=180