Question

xsuupra4=7supra9 determinati x

Answer 1

$\frac{x}{4}=\frac{7}{9}$

utilizam proprietatea proportiilor: Produsul mezilor=produsul extremelor

$\frac{x}{4}=\frac{7}{9} \\ \\x\cdot9=4\cdot7 \\ \\ x=28:9 \\ \\ x=3,1111111111=3,(1)$