The problem is ;

Question

10x+8-y

X= 2 Y=5

Every time I do it I get 23 but my teacher says I'm wrong . where am I wrong ? someone help me please .

Answer 1

I also get 23.

So, unless you have transcribed the problem incorrectly, the answer key is wrong. Double check that, and then show your teacher your work. Something doesn't add up, as it were...