Answer:
25a - 25
Step-by-step explanation:
15a - 20 + 10a = 5
15a + 10a -20 - 5
[tex]\\ \tt\longmapsto 15a-20+10a[/tex]
[tex]\\ \tt\longmapsto 15a+10a-20[/tex]
[tex]\\ \tt\longmapsto 25a-20[/tex]
Take 5common
[tex]\\ \tt\longmapsto 5(5a-4)[/tex]
