First off i'm gonna start by saying, that i hate my algebra class. I dunno if its the teacher or the material, but i find this stuff so hard ! With calc i get most of it but just some hard questions i need to ask on here... with algebra i get like NONE of the theory/proofs behind it which is why i can never solve proofs in class. I can get regular numerical questions though lol. Heres the problem:(adsbygoogle = window.adsbygoogle || []).push({});

Suppose (A-B)D=0 where A,B,D are matrices of appropriate sizes and D is invertible. Prove that A=B.

So of course A-B is zero, because 0 times D would of course yield 0. But i have nooo idea at all how to prove this using all the theorems we learned in class. This is an intro Lin Alg. course so we haven't done anything to complicated, just did the basics behind inverses and all that. Also, i lost a page of my notes, which i think might be important, because there aren't too many theorems that i have in my notes right now to work with :(

Any help would be really appreciated. THANKS :)

I know somehow you'd have to eliminate the D so that you are left with A-B= 0 which of course leads to A=B, but i have no clue how to do that :(

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# Inverse Proof!

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