1T 2012 høst LØSNING

Oppgave 1

a = -2 og punkt. (3,0)

<tex>0 = -2 \cdot 3 + b \\ b= 6 \\ dvs: \\ y=-2x+6</tex>

Oppgave 2

<tex>lg(2x+3) = 1 \\ 10^{lg(2x+3)} = 10^1 \\ 2x+3 =10 \\ x= \frac 72</tex>

Oppgave 3

<tex>\frac{(2x)^3x^2}{2^5x^{-1}} = 2^{3-5}x^{3+2+1}= \frac{x^6}{4}</tex>

Oppgave 4

<tex>\frac{x^2+6x+9}{x^2-9} = \frac{(x+3)(x+3)}{(x+3)(x-3)} = \frac{x+3}{x-3}</tex>

Oppgave 5

<tex> (\sqrt2 + \sqrt8)^2 = 2+2\sqrt2\sqrt8+8 = 18</tex>