Question

(a-b)(a+b)=a²-b²
Q 25x35
Q 49x51
Q 98x102
Q 77x83
Q 11x9

Answer 1

$q \: \: 25 \times 35 = {30}^{2} - {5}^{2} = 275 \\ q \: 49 \times 51 = {50}^{2} - {1}^{2} = 2499 \\ q \: \: 98 \times 102 = {100}^{2} - {2 }^{2} = 9996 \\ q \: \: 77 \times 83 = {80}^{2} - {3}^{2} = 6391 \\ q \: 11 \times 9 = {11}^{2} - {9}^{2} = 40$