Линейная функция задана формулой : f(x)= kx+3,5. Найдите значение k, если :
2) f(-5)=8,5
4) f(0,3)=6,2
ПОМОГИТЕ ПОЖАЛУЙСТА

f( - 5) = 8.5                                                    f(0.3) = 6.2

-5K + 3.5 = 8.5                                             0.3K + 3.5 = 6.2

-5K =5                                                           0.3K = 2.7

 K = -1                                                                К = 9