Question

dada a funçao f(x)=ax+b, sabendo se que f(1)=4 e f(-2)=10 . Escreva a funçao f(x) e calcule f(3)

Answer 1

f(x) = ax + b

f(1) = 4

f(-2) = 10

1a + b = 4 *(-1)

-2a + b = 10

-1a - b = -4

-2a + b = 10

-3a = 6 *(-1)

3a = -6

a = -6/3

a = -2

-2a + b = 10

-2*(-2) + b = 10

4 + b = 10

b = 10 - 4

b = 6

f(x) = -2x + 6

f(3) = -2*(3) + 6

f(3) = -6 + 6

f(3) = 0