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[tex]Sum:  + (add) \\ \\ 5:5 \\  \\ z:z \\ \\ 4:4 \\ \\  divided  by: division \\ \\ 2:2 \\ \\ is: =  \\ \\ 7:7 [/tex]
Answer: [tex] \frac{5z +4}{2}  = 7 [/tex] 
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[tex] \frac{5(2)+4}{2} [/tex]
[tex]5(2) = 10 [/tex]
[tex]10 + 4 = 14 [/tex]
[tex] \frac{14}{2}  = 7 [/tex]
Answer: [tex]z = 2[/tex]
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