Help plz need the answer asap

hey, um i need your help with something ill answer your question if u brainlist me on this coz the thing is their gonna ban me if i dont get 10 brainlist in 2 weeks, pls help a stranger out. ill owe u!! and im so dissapointed because i have heaps of work thats due i rlly need this please.

Step-by-step explanation:

The video is blocked but you can type your question on here1

Step-by-step explanation:

answer: your answer is a

you are playing an adventure game on your computer. you come across a troll who won't let you pass and there is no other way to get to the other side of the river except over the bridge he is guarding.

the troll is a nerd. he takes great delight in watching people struggle with his problems. very few get them. he only gives you one chance and then he changes the puzzle. you have to solve this one.

before you are four blocks. they are numbered 11,6, -7,21.

he tells that the answer he wants is minus and between -1 and - 2. you can use +, -, ×, ÷   ( and ) as many times as you like or no times at all. you don't like the way he's looking at you, but you need to cross the bridge. what do you do?