1.a)3⁴-4³=81-64=17
b)27dm=270cm
270cm-25cm=245cm=2,45m
2.a)5/12, 7/18 si 0,(3)
Pentru asta, trebuie sa aducem la numitor comun fractiile
5/12, 7/18 si 1/3
Numitorul comun este 36, deci amplificam prima fractie cu 3, a doua cu 2 iar a treia cu 12 si avem
15/32>14/36>12/36
b)81-16=65
3.m(∡AOD)=180°-110°=70°=m(∡DOC)(OD-bisectoare)
m(∡COB)=180°-140°=40°=>m(∡COF)=20°
4.F(x)=ax-3a=a(x-3)
G(x)=bx-3b=b(x-3)
F(a)=a(a-3)
G(a)=b(a-3)
[F(a)-G(a)]/(a-b)=[a(a-3)-b(a-3)]/(a-b)=(a-b)(a-3)/(a-b)=(a-3)
5.360°:30°=12 parti
12 parti__________120 levi
1parte___________x
x=120/12=>x=10 elevi
6.a)√12=2√3
-√75=-5√3
√27=3√3
Media aritm=(2√3-5√3+3√3)/3=0
b)√12=2√3
√48=4√3
Media geom.=2√3x4√3=2x4x3=24
7.N=x²-4+y²-2xy
a)N=(x²-2xy+y²)-2²
=(x-y)²-2²
b)N=(x-y+2)(x-y-2)
8.a)AC=a√2=>EC²=a²+2a²=>EC²=3a²=>EC=a√3
