Question

1)2,5 · (4,3 - 2,1) + 10 x = 17,3;2)100 x -8,7. (21,3 + 8,7) = 0;​

Answer 1

1)

$2.5(4.3 - 2.1) + 10x = 17.3 \\ 2.5 \times 2.2 + 10x = 17.3 \\ 5.5 + 10x = 17.3 \\ 10x = 17.3 - 5.5 \\ 10x = 11.8 \\ x = 1.18$

2)

$100x - 8.7 \times (21.3 + 8.7) = 0 \\ 100x - 8.7 \times 30 = 0 \\ 100x - 261 = 0 \\ 100x = 261$

Answer 2

To solve the given system of linear equations, let's denote $x$ as the unknown variable and proceed to solve each equation step by step.

1. $2.5 \times (4.3 - 2.1) + 10x = 17.3$

First, solve the expression inside the parentheses:

$4.3 - 2.1 = 2.2$

Next, multiply by 2.5:

$2.5 \times 2.2 = 5.5$

Now, the equation becomes:

$5.5 + 10x = 17.3$

Subtract 5.5 from both sides to isolate $x$:

$10x = 17.3 - 5.5 = 11.8$

Now, divide by 10 to find $x$:

$x = \frac{11.8}{10} = 1.18$

2. $100x - 8.7 \times (21.3 + 8.7) = 0$

First, solve the expression inside the parentheses:

$21.3 + 8.7 = 30$

Next, multiply by 8.7:

$8.7 \times 30 = 261$

Now, the equation becomes:

$100x - 261 = 0$

Add 261 to both sides to isolate $x$:

$100x = 261$

Now, divide by 100 to find $x$:

$x = \frac{261}{100} = 2.61$

So, the solutions for the system of equations are: $x = 1.18$ for the first equation and $x = 2.61$ for the second equation.