-11[-3(-7--15)+18]?

Answer 1

- 11[-3{- 7 - (- 15)} + 18] =

- 11 [- 3 { - 7 + 15} + 18] =

- 11 [ - 3 { + 8} + 18] =

- 11[ - 24 + 18] =

- 11[ - 6]

66

- - - - - - - - - -s-

Answer 2

Do this step by step

Start out by working out -7 - -15 to get

-11[-3(8)+18]

Then work out -3(8) to get

-11(-24+18)

Combine the -24 and 18 to get

-11(-6)

Finally multiply to get a final answer of
66

Answer 3

It should be made clear that you do the part inside the parenthesis first, then the part inside the brackets. Soon you will recognize situations where it makes no difference (not here).
Are the minus signs confusing you? After a bit of homework it almost becomes second nature to use the proper sign.
The math is easy. You can do it.