The first bracket:

(5 + 6 × 3) = 5 + 18 = 23

The second bracket:

(4 + 2) = 6

So we have, since we need to work from left to right:

12 × 23 ÷ 6 = 46

So

12(5 + 6 × 3) ÷ (4 + 2) = 46