Odpowiedź:
a) y = ax+b
3 = a×1 + b
2 = a×(-4) + b
b = 3 - a
2 = -4a + 3 - a
2 - 3 = -5a
5a = 1
a = 1/5
b = 3 - 1/5 = 2 4/5
[tex]y = \frac{1}{5}x \: + \: 2\frac{4}{5} [/tex]
b) y = ax + b
0 = a×(-3) + b
4 = a×0 + b
b = 4
3a = 4
a = 4/3
[tex]y = 1 \frac{1}{3}x \: + 4[/tex]
c) y = ax + b
-1/5 = a×3 + b
3 = a×(-3) + b
(dodajemy obustronnie)
2 4/5 = 2b
14/5 = 2b
14 = 10b
b = 1,4
3a = 1,4 - 3
3a = - 1,6
a = - 16/30
a = - 8/15
[tex]y = - \frac{8}{15}x + 1.4[/tex]
