Respuesta :

Answer: F=140

Step-by-step explanation:

720=(x-60)+(x-40)+(x-20)+130+120+110

720-130-120-110=3x-120

360=3x-120

360+120=3x

480=3x

480/3=x

160=x

F=160-20

Next problem

102+31+x=180

133+x=180

x=180-133

x=47