Answer:
[tex] \sf \pink{3ac - 12c + 3ad + 15d}[/tex]
Step-by-step explanation:
[tex] \sf \purple {3c(a - 4) + 3d(a + 5)}[/tex]
[tex] \sf \purple{3ca + 3c( - 4) + 3d(a + 5)}[/tex]
[tex] \sf \purple{3ac + 3( - 4)c + 3da + 3d \times 5}[/tex]
[tex] \sf \pink{3ac - 12c + 3ad + 15d}[/tex]
