Вычислите:в)42,4²-42,3² г)6.8²-3.2²

Question

Вычислите:в)42,4²-42,3² г)6.8²-3.2²

Answer 1

X^2 - y^2 = (x-y)(x+y)
1) 42.4^2 - 42.3^2 = (42.4-42.3)(42.4+42.3) = 0.1 * 84.7 = 8.47
2) 6.8^2 - 3.2^2 = (6.8-3.2)(6.8+3.2) = 3.6*10 = 36