Question

ajutor toate exercitiile

Answer 1

1. a)$\frac{1}{3}$
b)$\frac{5}{3}$
c)$\frac{3}{3}$
d)$\frac{2}{3}$
2. a) $\frac{8}{2x+1}$ este supraunitara ⇒x∈{1,2,3}
 $\frac{8}{2x+1}$ este supraunitara⇒2x+1<8
2x<7
x<3,5
b)$\frac{6}{x}$∈N⇒x∈{1,2,3,6}
$\frac{6}{x}$∈N⇒x|6 ⇒ x∈D₆={1,2,3,6}
c)$\frac{x+3}{x} = \frac{4}{3}$⇒x=9
(x+3)×3=4x
3x+9=4x
x=9
3. $\frac{1}{2}$ se amplifica cu 12 :$\frac{12}{24}$
$\frac{3}{4}$ se amplifica cu 6 :$\frac{18}{24}$
$\frac{5}{8}$ se amplifica cu 3 :$\frac{15}{24}$
$\frac{7}{12}$ se amplifica cu 2 :$\frac{14}{24}$
$\frac{11}{6}$ se amplifica cu 4 :$\frac{44}{24}$
4.a)
$\frac{162}{192}$ se simplifica cu 6 :$\frac{27}{32}$
b)$\frac{2^{8} +2^{9} }{96}$=$\frac{2^{8}(1+2) }{96}$ se simplifica prin 96=2³
c)$\frac{20+a+10a+2}{121}$=$\frac{22+11a}{121}$=
=$\frac{11(2+a)}{121}$ se simplifica prin 11 :$\frac{2+a}{11}$
5. $\frac{3}{5}$ ×15 = 9
15-9=6 bomboane ramase
6. x= nr de bani 
$\frac{3}{7}$ din x =16
$\frac{3x}{7}$=16
3x=16×7
x=$\frac{112}{3}$
x=37,(3)lei