Odpowiedź:
1)
5x + y = 10
10x + y = 40
Odejmujemy równania
5x - 10x + y - y = 10 - 40
- 5x = - 30
5x = 30
x = 30/5 = 6
5x + y = 10
5 * 6 + y = 10
30 + y = 10
y = 10 - 30 = - 20
2)
a)
f(x) = 5x + 6x²+ 1
f(0) = 5 * 0 + 6 * 0² + 1 = 0+ 0 + 1 = 1
b)
g(x) = 10x² + 5x - 10
g(-1) = 10 * (-1)² + 5 * (-1) - 10 = 10 * 1 - 5 - 10 = 10 - 5 - 10 = - 5
