PDF chapter test TRY NOW

Compute these products using the suggested identity.

\(398 × 402\) using the identity for \((a + b)(a - b)\)
 
Answer:
 
\((a - b)(a + b)\) \(=\) iiii
 
Rewrite the product as i2i+2.
 
\(398 × 402\) \(=\)