Question

Va rog faceți cat puteți din exerciți ,macar 2-3 .Va rog mult dau coroană!!!

Answer 1

1) a) 1.2+x = 3.3 => 1.2+2=3.2 => Nu verifica ecuatia!
b) x-1.5 < 0.5 =>$2-1.5\leq0.5=>0.5/leq0.5$ => Verfica inecuatia!
2) a) x/0.4 - 1.1 = 1.9 => x/0.4=1.9+1.1 => x=3*0.4=1.2;
b) 0.1+x>1.6
=> x > 1.6-0.1 => x > 1.5
3) 0.03+0.2x<1.3 => 0.2x< 1.3-0.03 => x< $\frac{1.27}{0.2}=> x<6.35$

Answer 2

6)

Dacă primul număr este x, rezultă că al doilea număr va fi 2x

[tex]\it m_a=\dfrac{x+2x}{2} =10,05 \Rightarrow \dfrac{3x}{2} =10,05 \Rightarrow 3x=2\cdot10,05 \Rightarrow \\\;\\ \\\;\\ \Rightarrow 3x= 20,1 \Rightarrow x = 20,1:3 \Rightarrow x=6,7[/tex]

4)

[tex]\it x:2,05=6,8\ \ rest\ 0,01 \Rightarrow x=2,05\cdot6,8+0,01 \Rightarrow \\\;\\ \Rightarrow x = 13,94+0,01 \Rightarrow x = 13,95[/tex]

3)

[tex]\it 0,03+0,2x\ \textless \ 1,3 \Rightarrow 0,2x\ \textless \ 1,3-0,03\Rightarrow 0,2x\ \textless \ 1,27|_{\cdot100} \Rightarrow \\\;\\ \Rightarrow 20x\ \textless \ 127\Rightarrow x\ \textless \ \dfrac{127}{20} \Rightarrow x\ \textless \ \dfrac{120+7}{20}\Rightarrow x\ \textless \ 6\dfrac{7}{20} \ \ \ (*)[/tex]

$\it \ x\in \mathbb{N} \stackrel{(*)}{\Longrightarrow} x\in\{0,\ \ 1,\ \ 2,\ \ 3, \ \ 4, \ \ 5,\ \ 6\}$