Question

Determine a função f(X) = ax + b, quando f (-2) = 4 e f (4) = 8​

Answer 1

f(x) = ax + b

f(-2) = a(-2) + b

4 = -2a + b

2a + 4 = b

f(x) = ax + b

f(4) = a(4) + b

8 = 4a + b

8 - 4a = b

2a + 4 = 8 - 4a

6a = 4

a = 4/6 = 2/3

b = 2a + 4

b = 2(2/3) + 4

b = 4/3 + 4

b = 4/3 + 12/3

b = (4 + 12)/3

b = 16/3

f(x) = ax + b

f(x) = 2/3 . x + 16/3

f(x) = 2/3 . (x + 8)