Problem: whats the answer for 5[21-(-67-69)]
whats the answer for 5[21-(-67-690]
There is no need for brackets; parentheses
can be nested.
5(21 - (-67 - 69))
Always start in the deepest nested parentheses.
5(21 - (-67 - 69))
5(21 - (-136))
5(21 + 136)
5(157)
785