Question

stiind ca a si b sunt numere nenule si a/5=b/7 ,atunci egalitatea 3a+2b/5a-4b=-29/3 este: a)adevarata b)falsa ​

Answer 1

Răspuns:

$\frac{a}{5} = \frac{b}{7} < = > a = \frac{5b}{7}$

$\frac{(3 \times \frac{5b}{7} + 2b )}{(5 \times \frac{5b}{7} - 4b)} = \frac{(15b + 14b)}{(25b - 28b)} = \frac{29b}{ - 3b} = - \frac{29}{3} adevarat$