Question

(a+1)(a-1)(a² +1)-(9+a²)² при a=⅓

Answer 1

Ответ:

-84

Пошаговое объяснение:

=(a²-a+a-1)(a²+1)-(81+18a²+a⁴)=a⁴+a²-a³-a+a³+a-a²-1-81-18a²-a⁴(числа сокращаются)=-18a²-82

Если a=⅓, то -18a²-82=-18×(⅓)²-82=-18×⅑-82=-2-82=-84

Answer 2

To evaluate the expression (a+1)(a-1)(a² + 1) - (9 + a²)² at a = 1/3, you simply substitute the value of a into the expression and perform the calculations. Let's break it down step by step:

Given expression: (a+1)(a-1)(a² + 1) - (9 + a²)²

Substitute a with 1/3: (a + 1/3)(a - 1/3)(a² + 1) - (9 + (1/3)²)²

Now calculate the terms: a + 1/3 = 1/3 + 1/3 = 2/3 a - 1/3 = 1/3 - 1/3 = 0 a² + 1 = (1/3)² + 1 = 1/9 + 9/9 = 10/9 (1/3)² = 1/9 (9 + (1/3)²)² = (9 + 1/9)² = (81/9 + 1/9)² = (82/9)²

Substitute these values back into the expression: (2/3)(0)(10/9) - (82/9)²

Since one of the terms is 0, the entire expression simplifies to: 0 - (82/9)²

Calculate: -(82/9)² = -6724/81

So, the value of the expression at a = 1/3 is: 0 - 6724/81 = -6724/81.