Question

4X^2- 4xy + y^2 - 8x + 4y - 3, если 2x-y=5

Answer 1

Ответ:

2

Объяснение:

1) упростим наше выражение:

$4 {x}^{2} - 4xy + {y}^{2} - 8x + 4y - 3 = {(2x - y)}^{2} - 4(2x - y) - 3$

2) подставим в полученное ввражение 2х-у=5

${(2x - y)}^{2} - 4(2x - y) - 3 = {5}^{2} - 4 \times 5 - 3 = 25 - 20 - 3 = 2$

Answer 2

To find the value of the expression $4X^2 - 4xy + y^2 - 8x + 4y - 3$ when $2x - y = 5$, we need to substitute the value of $y$ in terms of $x$ from the given equation into the expression. Let's solve for $y$ in terms of $x$ from $2x - y = 5$:

$y = 2x - 5$

Now, substitute this value of $y$ in the expression:

$4X^2 - 4xy + y^2 - 8x + 4y - 3$

$= 4X^2 - 4x(2x - 5) + (2x - 5)^2 - 8x + 4(2x - 5) - 3$

$= 4X^2 - 8x^2 + 20x - (2x - 5)^2 - 8x + 8x - 20 - 3$

$= 4X^2 - 8x^2 + 20x - (4x^2 - 20x + 25) - 12$

$= 4X^2 - 8x^2 + 20x - 4x^2 + 20x - 25 - 12$

$= 4X^2 - 8x^2 - 4x^2 + 20x + 20x - 25 - 12$

$= 4X^2 - 12x^2 + 40x - 37$

So, the simplified expression is $4X^2 - 12x^2 + 40x - 37$.