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
You worked a total of 35 hours that week.
4+3 is 7hours a day times 5 days which is 35.
15^15. Answer is 15 to the 15th power because by laws of exponents when you have a base with power m over same base with power n it is base to the m-n power. Simply you subtract the exponents when dividing with same base.