Answer:
= 5 ( 12d + 23f )
Explanation:
-2(5d-9f)+7f-10(-9f-7d)
Open parenthesis
= -10d + 18f + 7f + 90f + 70d
Collect like terms
= -10d + 70d + 18f + 7f + 90f
= 60d + 115f
Factorise
= 5 ( 12d + 23f )
Therefore,
-2(5d-9f)+7f-10(-9f-7d) in its simplest form is 5 ( 12d + 23f )