Question 578003
I'm guessing there is a typo and it's supposed to be 4*100.... assuming that:

((8*1000)+ (4*100)+(2*10)+(8*1))
(-(3*1000)+(6*100)+(6*10)+(1*1))
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multiply it out and distribute the negative:

8000 + 400 + 20 + 8 = 8428
- (3000 + 600 + 60 + 1) = - (3661)

8428 - 3661 = 4767, which can be re-written as 

4000 + 700 + 60 + 7 or

(4*1000)+(7*100)+(6*10)+(7*1); answer B