Question

Sabendo que (0;0), (1;1) e (x;2) são pontos colineares, então x vale:

Answer 1

(0;0) , (1;1) e ( x; 2)
| 0 0 1| 0 0 |
| 1 1 1| 1 1 | = 0     -->
| x 2 1| x  2 |

(0*1*1) + (0*1*x) + (1*1*2) = 0 + 0 + 2.
(0*1*1) + (0*1*2) + (1*1*x) = 0 + 0 + x.

(0+0+2) - (0+0+x) = 0
2 - x = 0
x = 2.