Aflati-l pe x din proportia:
6x+7 supra 5x-21 = 7 supra 8
Dau coroana + 20 puncte


Răspuns :


[tex] \frac{6x + 7}{5x - 21} = \frac{7}{8} \\ \\ 6x + 7 = \frac{7}{8}(5x - 21) \\ \\ 6x + 7 = \frac{7(5x - 21)}{8} \\ \\ 48x + 56 = 7(5x - 21) \\ \\ 48x + 56 = 35x - 147 \\ \\ 48x + 56 - 35x = - 147 \\ \\ 13x + 56 = - 147 \\ \\ 13x = - 147 - 56 = - 203 \\ \\ = > x = - \frac{203}{13} [/tex]