Question

I Aflati x din proportile: x/65 = 4/10 (0, 4)/x = (1, 75)/(0, 7) 3) 2x 17 = 4 5 :4) 9 x+1 = 3 x+2​

Answer 1

Explicație pas cu pas:

1)

$\frac{x}{65} = \frac{4}{10} \\ x = \frac{65 \times 4}{100} = > x = \frac{13}{5} = 2.6$

2)

$\frac{0.4}{x} = \frac{1.75}{0.7} \\ x = \frac{0.4 \times 0.7}{1.75} = > x = \frac{4}{25} = 0.16$

3)

$\frac{2x}{17} = \frac{4}{5} \\ x = \frac{17 \times 4}{2 \times 5} = > x = \frac{34}{5} = 6.8$

4)

$\frac{2}{x + 1} = \frac{3}{x + 2}$

$3(x + 1) = 2(x + 2) \\ 3x + 3 = 2x + 4 \\ 3x - 2x = 4 - 3 \\ x = 1$