12.1 and 12.2 Review (10/12)

 $-3T\ -2T\ -5-4$  

Which are like terms?

 $-3T\ and\ -2T\ \left(have\ same\ letter\right)$  

 $-5\ and\ -4\ \left(both\ have\ no\ letter\right)$  

Combine ( $-3T\ +\ -2T\ =\ -5T$  

 $-5\ +\ -4\ =\ -9$  

answer:  $-5T\ \ \ +\ -9$  

 $-8X\ +25\ \ \ \ \ when\ X=5$  

Substitute 5 for X 

 $-8\ \left(5\right)\ +\ 25\ =$  

PEMDAS - multiplication first

 $-40\ +\ 25$  

One negative, one positive so you

Subtract! 40 minus 25 = 15....answer is negative because bigger number is negative.  $-15$