To do this, we're going to use the order of operations (PEMDAS):
P - Parentheses
E - Exponents
M - Multiplication
D - Division
A - Addition
S - Subtraction
First let's do parentheses, there isn't anythig in parentheses we need to simplify, so we can skip this step.
Next let's look for exponents. I see we have a [tex]5^2[/tex] so let's replace that with [tex]5^2=25[/tex]:
[tex]-3(25)-(-2)(-8)[/tex]
Now let's look for multiplcation. We know that things that are right next to eachother in parentheses represent multiplcation, so let's simply this more:
[tex]-3(25)=-75[/tex]
[tex](-2)(-8)=16[/tex]
[tex]-75-16[/tex]
And now we're left with a simple problem we know how to solve.
Answer: [tex]-91[/tex]
Hope this helps!