[tex]4 - 5(2 - 1) = \: ?[/tex]
PEMDAS states to do what's in the parenthesis first...
[tex]4 - 5(1)[/tex]
PEMDAS states to multiply 5 by 1 next...
[tex]4 - 5[/tex]
PEMDAS states to subtract 4 by 5 next...
[tex] = - 1[/tex]
~~
I hope that helps you out!!
Any more questions, please feel free to ask me and I will gladly help you out!!
~Zoey