Question

5{-3.4k-7} + {3k+21}

Answer 1

First step is to do distributive property.
 
so you multiply 5 by -3.4k and -7 

your equation now is -17k-35+(3k+21)
 
Then you add like terms 

add -17k+3k to give you -14k-35+21 
 
then you add like terms again

add -35+21 to give you -14

so now your equation is -14k-14 

So that is your answer simplified