Răspuns:
Explicație pas cu pas:
[tex]ex11. x+\frac{1}{2}*x=4,5, \frac{2}{2}x+ \frac{1}{2}*x=4\frac{1}{2} , \frac{3}{2}x=\frac{3}{2},\\x=\frac{9}{2}:\frac{3}{2}=\frac{9}{2}*\frac{2}{3}=3\\ex 12\\x+x+1+x+2=54, 3x=54-3, x=51:3=17.\\17; 18; 19\\ex 13\\x-\frac{2}{5}x=37+23, \frac{5}{5}x-\frac{2}{5}x=60, \frac{3}{5}x=60, x=60:\frac{3}{5}=60*\frac{5}{3}=100\\ex 14\\x-\frac{3}{4}x+18=\frac{1}{2}x, \frac{4}{4}x-\frac{3}{4}x+18=\frac{2}{4}x,\\\frac{4}{4}x-\frac{3}{4}x-\frac{2}{4}x=-18, -\frac{1}{4}x=-18, x=-18:-\frac{1}{4}=-18*(-4)=72\\x=72[/tex]
