Question

вычисли:
7,2^2-7,8^2
------------------------------
7,2^0*0,4-7,8^0*0,8
^ = степень
------ = дробная черта

Answer 1

a² - b² = (a - b)(a + b)

a^0 = 1

7.2^2 - 7.8^2 = (7.2 - 7.8)(7.2 + 7.8) = -0.6 * 15 = -9

7.2^0*0.4 - 7.8^0*0.8 = 0.4 - 0.8 = -0.4

-9 / -0.4 = 9 : 4/10 = 9 * 5/2 = 45/2 = 22.5