Даю 50 Баллов за пять примеров!

① 1) 2,99² = $(\frac{299}{100})^{2} = \frac{89401}{10000}$

2) 3,01² = $(\frac{301}{100})^{2} = \frac{90601}{10000}$

3) 9,99 = $\frac{999}{100}$

② 1) 89²➖2*89*81² = 7921 ➖ 14418 ➕ 6561 = 64

2) 77²➕2*77*23➕23² = 5929➕3542➕529 = 10000

3) 111²➖2*111*11+11² = 12321 ➖ 2442 ➕ 121 = 10000

4) 9999² ➖ 2*9999*1+1² = 9999² ➖ 19998 + 1 = 9999² ➖ 19997

5) 10002² ➖ 2*10002*2+2² = 10002² ➖ 40008 ➕ 4 = 10002² - 40004