Respuesta :

tonb

Answer:

12

Step-by-step explanation:

Then the -12 and +12 will cancel out, so you're left with a clean isolated r on the left:

r -12 +12 = 19 + 12

r = 31

12

So,
r+ -12+ 12 = 19+ 12
r+ 0 = 31
R=31