Respuesta :

scrublord8710

Answer:

11

Step-by-step explanation:

All angles on a triangle equal 180. 80+60=140.

Now to solve for x, we set it to equal 40 for 180-140.

40=3x+7. 40-7=33

33=3x 33/3=11

x=11
Every triangle has to add up to 180 degrees. So if you already have 140 degrees, that’s what the 3x+7 has to add up to.
Ver imagen schanlle89