Răspuns:
Explicație pas cu pas:
1. 4(2t-1)-7(t-3)=
8t-4-7t+21=
t+17
2. E(x)=(x+1)²-x(x+2)
E(x)=x²+2x+1-x²-2x=1 ∈N
3.
[tex]n=(\frac{3}{\sqrt{3}}+1)^{2} +(1-\sqrt{3} )^{2} =(\sqrt{3} +1)^{2}+ (1-\sqrt{3} )^{2} =3+2\sqrt{3} +1+1-2\sqrt{3}+3=8[/tex]
8∈N
4. (x+2)²=6x+7
x²+4x+4-6x-7=0
x²-2x-3=0
Δ=4+12=16
[tex]x_{1}=\frac{2+4}{2}=3\\x_{1}=\frac{2-4}{2} =-1[/tex]
