Question

sendo f(x-4)=3x+1, determine:
f(5)
f(-3)
f(-1) - f(-2)

Answer 1

Seja x - 4 = 5 => x = 9
f(5) = 3.9 + 1 => f(5) = 27 + 1 => f(5) = 28

x - 4 = -3 => x = -3 + 4 => x = 1
f(-3) = 3.1 + 1 => f(-3) = 3 + 1 => f(-3) = 4

x - 4 = -1=> x =  -1 + 4 => x = 3
f(-1) = 3.3 + 1 => f(-1) = 10
x - 4 = -2 => x = -2 + 4 => x = 2
f(-2) = 3.2 + 1 => f(-2) = 7

f(-1) + f(-2) = 10 + 7 = 17