HELP!!
Which missing item would complete this beta decay reaction?

x = -4

step-by-step explanation:

- 20 - 4(x + 3) = 4x

=> -20 - 4x - 12 = 4x

=> - 32 -4x = 4x

=> -32 = 4x + 4x

=> - 32 = 8x

=> -32/8 = x

=> -4 = x

the 3rd on is correct

step-by-step explanation:

i agree because i see the other persons thinking is clear

ranks (& how to earn them):

-beginner (needs at least 0 points & 0 brainliest answers)

- hand (needs at least 100 points & 0 brainliest answers)

-ambitious   (needs at least 250 points & 0 brainliest answers)

-virtuoso (needs at least 500 points & 5 brainliest answers)

-expert   (needs at least 1,000 points & 10 brainliest answers)

-ace (needs at least 3,000 points & 15 brainliest answers)

-genius   (needs at least 15,000 points & 50 brainliest answers)

how to award brainliest:

you must wait until 2 people answer to award brainliest. i'm pretty sure that it should be next to the "" and "comments" buttons.