A = ( − 2; 5)
B = ( c ; c + 5)
Mamy
c + 5 = − 2 ⇒ c = − 7 oraz B = ( − 7; − 2)
Prosta AB :
y = a x + b
5 = −2a + b
−2 = − 7a + b
−−−−−−−−−−−−−−−− odejmujemy stronami
5 − (−2) = ( −2a + b) − ( − 7a + b)
7 = 5a
| 7 | ||
a = | ||
| 5 |
| 7 | 14 | 4 | 4 | |||||
b = 5 + 2a = 5 + 2* | = 5 + | = 5 + 2 | = 7 | |||||
| 5 | 5 | 5 | 5 |
| 7 | 4 | |||
y = | x + 7 | |||
| 5 | 5 |
| 7 | 4 | ||
x + 7 | = 0 | ||
| 5 | 5 |
| 7 | 39 | 5 | |||
x = − | / * | ||||
| 5 | 5 | 7 |
| 39 | 4 | |||
x = − | = −5 | |||
| 7 | 7 |