PLEASE HELP WILL MARK BRAINLIEST

Answer:
A
Step-by-step explanation:
Expressing the identity in terms of a and b
(a + b)³ = a³ + b³ + 3ab(a + b)
Subtract 3ab(a + b) from both sides , then
a³ + b³ = (a + b)³ - 3ab(a + b) ← substitute given values
a³ + b³ = 12³ - 3(7)(12) = 1728 - 252 = 1476
Step-by-step explanation:
I hope you get it. you have to substitute and also find the value of a3 + b3