Question

(12−4)−{(7−3)−[4−(4+4−6)+(3+4−7)]}

Answer 1

\left(12-4\right)-\left(7-3\right)-\left[4-\left(4+4-6\right)+\left(3+4-7\right)\right]
=8-\left(7-3\right)-\left[4-\left(4+4-6\right)+\left(3+4-7\right)\right]
=8-4-\left[4-\left(4+4-6\right)+\left(3+4-7\right)\right]
=8-4-2
=2