a. Expand (3 + 2x)⁴ in ascending powers of x, giving each coefficient as an integer.

b. Hence, or otherwise, write down the expansion of (3 − 2x)⁴ in ascending powers of x.

c. Hence by choosing a suitable value for x show that (3 + 2 √2)⁴ + ( 3 − 2√2)⁴ is an integer and state its value.