Question

-2(2,7х-1)-6-3,4х)+8(0,4х-2) и вычислите его значение при х=-2

Answer 1

Ответ:

Решение :

-2(2,7*(-2)-1)-6-3,4*(-2))+8(0,4*(-2)-2)= - 2*(-4,5 - 6+6,8) +8*(-2,8)=7,4-22,4 = - 15

Ответ : - 15

Answer 2

To evaluate the expression -2(2,7х-1)-6-3,4х)+8(0,4х-2) when x = -2, we'll substitute -2 for the variable x and perform the calculations step by step:

Step 1: Replace x with -2 in the expression: -2(2,7*(-2)-1)-6-3,4*(-2))+8(0,4*(-2)-2)

Step 2: Simplify the expressions within the parentheses: -2(2, -5 - 1) - 6 - 3,4 * (-2) + 8(0, -0.8 - 2)

Step 3: Perform the operations inside the parentheses: -2(2, -6) - 6 + 3,4 * 2 + 8(0, -2.8)

Step 4: Multiply the constants: -4, -12 - 6 + 6,8 - 22.4

Step 5: Combine the terms: -16 - 28.4

Step 6: Perform the final subtraction: -44.4

Therefore, when x = -2, the value of the expression -2(2,7х-1)-6-3,4х)+8(0,4х-2) is -44.4.