Question

4 (5х -3у) – 6( 3х – у), если х - 3у = 2,1

Answer 1

Ответ:

4,2

Пошаговое объяснение:

4 (5x – 3y) – 6 (3x – y) = 4 × 5x – 4 × 3y – 6 × 3x + 6 × y = 20x – 12y – 18x + 6y;

20x – 18x – 12y + 6y = x(20 – 18) – y(12 – 6) = 2x – 6y = 2(x – 3y).

Подставляем значение х-3у

2 × 2,1 = 4,2

Answer 2

To find the value of the expression 4(5x - 3y) - 6(3x - y) when x - 3y = 2.1, we need to first substitute the value of (x - 3y) into the expression and then simplify it.

Given: x - 3y = 2.1

Step 1: Substitute the value of (x - 3y) into the expression:

4(5x - 3y) - 6(3x - y)

Step 2: Replace (x - 3y) with 2.1:

4(5x - 3y) - 6(3x - y) = 4(5x - 3(2.1)) - 6(3x - 2.1)

Step 3: Simplify the expression:

Now, distribute the constants to their respective terms:

4(5x - 6(2.1)) - 6(3x - 2.1)

Calculate the values in the parentheses:

4(5x - 12.6) - 6(3x - 2.1)

Expand the multiplication:

20x - 50.4 - 18x + 12.6

Combine like terms:

(20x - 18x) + (12.6 - 50.4)

2x - 37.8

So, the value of the expression 4(5x - 3y) - 6(3x - y) when x - 3y = 2.1 is 2x - 37.8.