Partea I
1.
[tex]\frac{1}{2} -\frac{1}{3} -\frac{1}{6}=\frac{3-2-1}{6} =0[/tex]
Raspuns: A) 0
2.
[tex]\frac{15}{100}\cdot 2500=15\cdot 25= 375[/tex]
Raspuns: C) 375
3.
x²-4=0
x²=4
x=±2
x∈N ⇒ x=2
Raspuns: B) 2
4.
a+b=20,4
a-b=10,4
Le adunam si obtinem:
2a=30,8
a=15,4
b=5
a>b
Raspuns: B) 15,4
5.
[tex]P=\frac{cazuri\ favorabile}{cazuri\ totale}[/tex]
Cazuri favorabile=2,4,6
Cazuri total=1,2,3,4,5,6
[tex]P=\frac{3}{6} =\frac{1}{2}[/tex]
Raspuns: B
6.
AM mediana
Mediana intr-un triunghi dreptunghic este egala cu jumatate din ipotenuza
AM=6 cm⇒ BC=12 cm
Raspuns: D) 12 cm
7.
Unghiuri adiacente complementare= au o latura comuna si suma celor doua unghiuri este 90°
Raspuns: A) 45°
8.
Raspuns: D) o infinitate
9.
ΔABC≡ΔDEF
∡A=∡D=34°
∡B=∡E=67°
∡C=∡F=180-(34+67)=79°
Raspuns: B) 79°
Partea a II-a
10.
Aducem la acelasi numitor comun 30 si vom elimina numitorul:
12x-36+40+8x+4=6x+21-11
20x+8=6x+10
14x=2
7x=1
[tex]x=\frac{1}{7}[/tex]
11.
[tex]\frac{x}{\frac{1}{2} }=\frac{y}{\frac{1}{0,(3)} } =k\\\\x=\frac{k}{2} \\\\y=3k\\\\\frac{x+y}{2} =6,8\\\\x+y=13,6\\\\\frac{k}{2} +3k=13,6\\\\k+6k=27,2\\\\k=3,8(857142)\\\\x=1,9(428571)\\y=11,6(571428)[/tex]
12.
Notam pret initial=x
[tex](x-\frac{5}{100}\cdot x)- (x-\frac{5}{100}\cdot x)\cdot \frac{20}{100} =1140\\\\\frac{95x}{100}-\frac{19x}{100}=1140\\\\ \frac{76x}{100}=1140\\\\ 76x=114000\\\\ x=1500\ lei[/tex]
Exercitii cu probabilitati gasesti aici: https://brainly.ro/tema/726874
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