Question

3. Using the identity (a + b)² = (a² + 2ab + b²), evaluate 122²

Answer 1

112²

Using Identity

(a + b)² = (a² + 2ab + b²)

Solution

⇛122²

⇛(100 + 22)²

⇛(100)² + 2 × 100 × 22 + (22)²

⇛10000 + 4400 + 484

⇛14400 + 484

⇛14884

Answer 2

$\\ \sf\longmapsto 122^2$

$\\ \sf\longmapsto (100+22)^2$

$\\ \sf\longmapsto 100^2+2(100)(22)+22^2$

$\\ \sf\longmapsto 10000+4400+484$

$\\ \sf\longmapsto 14400+484$

$\\ \sf\longmapsto 14884$