Answer:
[tex]\pmb{2(m+n+1)}[/tex]
Step-by-step explanation:
[tex]\\ \sf\bull\longmapsto 5m-3m+7n+2-5n[/tex]
[tex]\\ \sf\bull\longmapsto 2m+7n-5n+2[/tex]
[tex]\\ \sf\bull\longmapsto 2m+2n+2[/tex]
[tex]\\ \sf\bull\longmapsto 2(m+n+1)[/tex]
