Hiya! :D
My name is Violet, and I will be helping you on your question!
[tex]\sf{7j \: + 3 \: - 4j \: + \: 9}[/tex]
[tex]\sf{Group \: like \: terms:}[/tex]
[tex]\sf{= 7j \: - 4j \: + \: 3 \: + \: 9}[/tex]
[tex]\sf{Add \: the \: numbers:}~ 3 \: + \: 9 \: = 12}[/tex]
[tex]\sf{= 7j \: - \: 4j \: + \: 12}[/tex]
[tex]\sf{Add \: similar \: elements:}~ 7j \: - 4j \: = \: 3j}[/tex]
[tex]\sf{= 3j \: + \: 12}[/tex]
Hope It Helps ! ^-^
#LearnWithBrainly
[tex]\underline{Answer :}[/tex]
[tex]\huge \pmb {\frak{Violet}}[/tex]
