Compute these products using the suggested identity. (i) $46^2$ using Identity 1A for $(a + b)^2$ (ii) $397 \times 403$ using Identity 1C for $(a + b) (a - b)$ (iii) $91^2$ using Identity 1B for $(a - b)^2$ (iv) $43 \times 45$ using Identity 1C for $(a + b) (a - b)$