Pembahasan:
4⁻² + 4⁻¹ + 4⁰ = 1 ₊ 1 ₊ 1
4² 4¹
= 1 ₊ 1 ₊ 1
16 4
= 1 ₊ 4 ₊ 16
16 16 16
= 21
16