Answer:
10d² + 8
Step-by-step explanation:
Given
(11 + 4d²) - (3 - 6d²) ← distribute parenthesis, second by - 1
= 11 + 4d² - 3 + 6d² ← collect like terms
= (4d² + 6d²) + (11 - 3)
= 10d² + 8