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
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