Question

(2x+5)^2-4x^2-20x если x=0,23

Answer 1

(2x+5)^2-4x^2-20x

(2·0,23+5)^2-4·0,23^2-20·0,23

(0,46+5)^2-4·(23/100)^2-4,6

Ответ: 25

Answer 2

To find the value of the expression (2x+5)^2 - 4x^2 - 20x when x = 0.23, we substitute the value of x into the expression and evaluate it.

Let's calculate step by step:

(2x + 5)^2 - 4x^2 - 20x

First, substitute x = 0.23:

(2(0.23) + 5)^2 - 4(0.23)^2 - 20(0.23)

Simplify the expression within parentheses:

(0.46 + 5)^2 - 4(0.0529) - 4.6

Perform the addition within parentheses:

(5.46)^2 - 4(0.0529) - 4.6

Square 5.46:

29.8516 - 4(0.0529) - 4.6

Multiply 4 by 0.0529:

29.8516 - 0.2116 - 4.6

Perform the subtraction:

29.6396 - 4.6

Finally, subtract 4.6 from 29.6396:

25.0396

Therefore, when x = 0.23, the value of the expression (2x + 5)^2 - 4x^2 - 20x is 25.0396.