Question

6 [ 4 × ( 72 - 63 ) ÷ 3 ]

Answer 1

6((4*(72-63)/3))
6((4*9/3))
6((36/3))
6((12))
72

Answer 2

Do parenthesis first.
72 - 63 = 9, simplifies to:
6 [ 4 * (9) ÷ 3]
multiply 9 and 4, which is 36, divide that by 3, which equals, 12
6 [12]
12*6 = 72