Question

apply standard algebraic identities to find the value of the following
a) 49.8²
b) 98 × 102
c) 195 × 205​

Answer 1

Answer:

2840.04

9996

39975

Step-by-step explanation:

$1^{st} :49.8^{2} = ( 50 - 0.2 )^{2} = 50^{2} - 2(50)(0.2) + 0.2^{2} = 2500 - 20 + 0.04 = 2480.04\\2^{nd} : 98*102 = ( 100 - 2 )( 100 + 2) = 100^{2} - 2^{2} = 10000 - 4 = 9996\\3^{rd} :195 * 205 = ( 200 - 5 )( 200 + 5) = 200^{2} - 5^{2} = 40000 - 25 = 39975$