Own answer

Cyclist 1: $a_1=20t$
Cyclist 2: $a_2=-25t+150$

$a_1=a_2$ leads to $t=3\frac{1}{3}$(using the graphic calculator).
They meet after $3$ hours and $20$ minutes.

$3x-5=0$ so $3x=5$. It follows that: $x=\frac{5}{3}$. The points of intersection with the axes are: $(\frac{5}{3},0)$ and $(0,-5)$.

$x-4=0$ so $x=4$. The points of intersection with the axes are: $(4,0)$ and $(0,-4)$.

$-0.5x+4=0$ so $0.5x=4$ giving $x=8$. The points of intersection with the axes are: $(8,0)$ and $(0,4)$.

$-2(x+3)=0$ so $x+3=0$ giving $x=-3$. The points of intersection with the axes are: $(-3,0)$ and $(0,-6)$.

$75$ euros

$0.09$ euros

$g=87.50+0.10k$ where $g$ is given in € and $k$ in km

For each hour a similar increase of $35$ euros can be seen;

compare 5 hours worked with 10 hours worked, the costs do not double as well

$K=35\cdot 6+65=275$

$K=35\cdot 2\frac{5}{6}+65\approx 164.17$

$n=200$ gives $p=2.5\cdot 200-300=200$. The profit is € 200.

The expenses made to organise the party.

The takings per visitor (the entry fee).