Question

3x^3+x^2-3x-1 если x= 2/3 ответ полностью

Answer 1

3x³ + x² -3x-1=     сгруппируем похожие слагаемые
(3 x³ -3x)+( x² -1)=     вынесем из обоих скобок общие множители
3x( x² -1)+( x² -1)=     вынесем из слагаемых общий множитель
( x² -1)(3x+1)=     разобьём разницу квадратов
(x-1)(x+1)(3x+1).
Если x= 2/3, то
(x-1)(x+1)(3x+1)=
(2/3-1)(2/3+1)(3*2/3+1)=
-1/3  *5/3*3=-5/3=-1целая 2/3.

Answer 2

To find the value of the expression 3x^3 + x^2 - 3x - 1 when x = 2/3, simply substitute the value of x into the expression and perform the calculations:

Replace x with 2/3 in the expression: 3(2/3)^3 + (2/3)^2 - 3(2/3) - 1

Now, calculate each part of the expression:

1. (2/3)^3 = (2/3) * (2/3) * (2/3) = 8/27
2. (2/3)^2 = (2/3) * (2/3) = 4/9
3. 3 * (2/3) = 2

Now, plug the calculated values back into the expression:

3(8/27) + 4/9 - 2 - 1

Now, calculate the expression:

= 8/9 + 4/9 - 2 - 1

Combine like terms:

= (8/9 + 4/9) - 2 - 1 = 12/9 - 2 - 1 = 4/3 - 2 - 1 = 4/3 - 3 = (4 - 9) / 3 = -5/3

So, the value of the expression 3x^3 + x^2 - 3x - 1 when x = 2/3 is -5/3.