Question

Am nezoie neaparat ex 2 si 3, acum daca se poate !!!!

Answer 1

$x-1\leq 6 = > x\leq 7\\\\A=[1,2,3,4,5,6,7] = > cardA=7 \\\\\\\\\\\frac{5}{x+7}=\frac{4}{x+3} = > x=13, \frac{5}{20}=\frac{4}{16} < = > \frac{1}{4}=\frac{1}{4}$

2.b)7      3.d)13