Question

solve the following according to the given instructions.
Evaluate using suitable Identities.
2) (b-7)²
1.51²-49² 2.103×104​

Answer 1

(b-7)² =b² +49−14b

= b² −14b+49 [∵(a−b) =a²+b² −2ab]

1.51²-49²=(51+49)(51-49)=100(2)=200

2.103*104=(100+3)(100+4)=100²+(4+3)100+12=

10000+700+12=10712