Question

0,8(3a-14) -0.6(6a-8) При а= -3 целые 1/12​

Answer 1

Ответ:

простим выражение.

0,8 * (3 * a - 14) - 0,6 * (6 * a - 8);  

Раскроем скобки.

0.8 * 3 * a - 0.8 * 14 - 0.6 * 6 * a + 0.6 * 8 = 2.4 * a - 11.2 - 3.6 * a + 4.8;  

Приведем подобные.

(2.4 * a - 3.6 * a) + (-11.2 + 4.8) = a * (2.4 - 3.6) - (11.2 - 4.8) = -1.2 * a - (7 - 0.6) = -1.2 * a - 6.4;

Вычислим выражение при a = -3  1/12;

-1,2 * a - 6.4 = -1.2 * (-3 1/12) - 6.4 = 1.2 * 3 1/12 - 6.4 = 1.2 * 37/12 - 6.4 = 3.7 - 6.4 = -3 + 0.4 = -2.6.

Answer 2

To evaluate the expression 0.8(3a - 14) - 0.6(6a - 8) when a = -3, we substitute the value of a into the expression and perform the calculations.

First, let's substitute a = -3 into the expression: 0.8(3(-3) - 14) - 0.6(6(-3) - 8)

Now, we simplify each part of the expression:

0.8(3(-3) - 14) = 0.8(-9 - 14) = 0.8(-23) = -18.4

0.6(6(-3) - 8) = 0.6(-18 - 8) = 0.6(-26) = -15.6

Now, substitute the simplified values back into the expression:

-18.4 - (-15.6) = -18.4 + 15.6 = -2.8

Therefore, when a = -3, the value of the expression 0.8(3a - 14) - 0.6(6a - 8) is -2.8.