الاجابة
c(-3a) = (-3a)2 – 2(-3a)
c(-3a) = 9a2 + 6a
d(a + 4) = 3(a + 4)2 – 6(a + 4) + 4
d(a + 4) = 3(a2 + 8a + 16) – 6a – 24 + 4
d(a + 4) 3a2 + 24a + 48 – 6a – 24 + 4
d(a + 4) = 3a2 + 18a + 28
c(-3a) + d(a + 4) = 9a2 + 6a + 3a2 + 18a + 28
c(-3a) + d(a + 4) = 12a2 + 24a + 28