9. Faci un trapez ABCD, unde AB= baza mare, iar CD este baza mica.
AB=12cm
CD=0,8dm = 8cm
Linia mijlocie o notezi cu EF.
EF=[tex] \frac{B+b}{2} = \frac{12+8}{2} = \frac{20}{2}=10 cm [/tex]
10. x-8=-7 /+8 => x=-7+8 => x=1
11.5*[tex] (-1)^{4} + 6*( -5)^{5} = 5*1+6*(-3125)=5-18750=-18745[/tex]
12. A dreptunghi = [tex] 56 cm^{2} [/tex]
L=14 cm
l=?
A dreptunghi = L*l => 56 [tex] cm^{2} [/tex] = 14*l => l= [tex] \frac{56}{14} =\ \textgreater \ l=4 cm[/tex]
13.[tex] \frac{x+1}{2}= \frac{x-1}{3} =\ \textgreater \ 3*(x+1) = 2* (x-1) =\ \textgreater \ 3x+3 = 2x-2[/tex] =>3x-2x =-2-2 => x=-5
14. [tex] \frac{3x-1}{4}+ \frac{2x-3}{6} = \frac{11}{12} [/tex]
Amplifici fractiile cu 3 si, respectiv, 2 => 9x-3-4x-6=11 => 5x-9 = 11 => 5x=11+9 => 5x=20 => x=[tex] \frac{20}{5} =\ \textgreater \ x=4[/tex]
Daca vrei, ti le rezolv si pe rpimele 9. Da-mi mesaj daca vrei. :*
