Question

826. 1) 1,2d - 0,5(4d - 1) = -0,7(d - 2); 2) 0,3n - (2,6 - 0,9n) = 1,2n + 3.​

Answer 1

Ответ:

1)1,2 d - 0,5(4d-1)= - 0,7(d-2)

1,2d - 2d+0,5= - 0,7d+1,4

-0,8d+0,5= - 0,7d+1,4

-0,8d+0,7d=1,4-0,5

-0,1d=0,9

d= - 9

2)0,3n-(2,6-0,9n)=1,2n+3

0,3n-2,6+0,9n=1,2n+3

1,2n-2,6=1,2n+3

1,2n-1,2n=3+2,6

0=5,6

Нет решения

Answer 2

To solve these equations, we'll first simplify them and then isolate the variables (d and n).

1. $1.2d - 0.5(4d - 1) = -0.7(d - 2)$

Let's start by distributing the constants on the left side of the equation:

$1.2d - 0.5 * 4d + 0.5 = -0.7d + 1.4$

Now, simplify further:

$1.2d - 2d + 0.5 = -0.7d + 1.4$

Combine like terms:

$-0.8d + 0.5 = -0.7d + 1.4$

Now, let's get all the d terms on one side of the equation and constants on the other side:

$-0.8d + 0.7d = 1.4 - 0.5$

Combine like terms:

$-0.1d = 0.9$

Now, divide both sides by -0.1 to isolate d:

$d = \frac{0.9}{-0.1}$

$d = -9$

So, the solution to the first equation is $d = -9$.

2. $0.3n - (2.6 - 0.9n) = 1.2n + 3$

First, distribute the negative sign inside the parentheses:

$0.3n - 2.6 + 0.9n = 1.2n + 3$

Now, let's group like terms:

$0.3n + 0.9n - 1.2n = 3 + 2.6$

Combine like terms:

$0.3n = 5.6$

Now, divide both sides by 0.3 to isolate n:

$n = \frac{5.6}{0.3}$

$n = 18.67$

So, the solution to the second equation is $n = 18.67$.