Question

simplify the following products by expressing these as a difference of two squares.
1. 12.4×11.6
2. 30.9×29.1

Answer 1

$a. \: (12 + 0.4)(12 - 0.4) \\ {(12)}^{2} - {(0.4)}^{2} \\ 144 - 0.16 \\ 143.84 \\ b. \: (30 + 0.9)(30 - 0.9) \\ {(30)}^{2} - {(0.9)}^{2} \\ 900 - 0.81 \\ 899.19$

Answer 2

Answer:

1) 12.4×11.6

$(12+0.4)(12-0.4)$

$(12^2-0.4^2)$

$144- 0.16$

$143.84$

2) 30.9×29.1

$(30+0.9)(30-0.9)$

$30^2-0.9^2$

$(900-0.81)$

$899.19$