Answer:
16
Explanation:
To simplify, we have to start from the innermost parentheses and expand from there!
-3+{1-3[20+2(-6-7)]} -6-7=-13
-3+{1-3[20+2(-13)]} 2*-13=-26
-3+{1-3[20-26]} 20-26=-6
-3+{1-3[-6]} -3*-6=18
-3+{1+18} 1+18=19
-3+19 -3+19=16
16
I really hope this helps!! Have a wonderful day C: