Question

using the identity (a²-b²)=(a+b)(a-b), find(12.1)²-(7.9)²​

Answer 1

Answer:

84

Step-by-step explanation:

$a = 12.1 \\ b = 7.9 \\ {(12.1)}^{2} - {(7.9)}^{2} \\ = (12.1 + 7.9)(12.1 - 7.9) \\ = 20 \times 4.2 \\ = 84$