How to solve and what is the correct multiple choice answer?

0=0  

The input is an identity: it is true for all values

Step-by-step explanation:

3 ( 4 − 7 ) = − 2 1 + 1 2

Solve

Distribute

     3(4z−7)=−21+12z

1 2 − 2 1 = − 2 1 + 1 2

Rearrange terms

1 2 − 2 1 = − 2 1 + 1 2

1 2 − 2 1 = 1 2 − 2 1

add  2 1   to both sides of the equation

12 − 2 1 = 1 2 − 2 1

1 2 − 2 1 + 2 1 = 1 2 − 2 1 + 2 1

simplify

Add the numbers

12z = 12z

Subtract 12 from both side of the equation

1 2 = 1 2

12z- 12z= 1 2 − 12

Simplify, combine like Terms

0=0

Hope this helps.

answer: 12

step-by-step explanation: