Answer:
y = (-2) 2^(x+1)
Step-by-step explanation:
Whenever x increases from by 1, y decreases by doubling (the negative value), so the exponent is -2
When x = -1, y = -2.
So the exponential equation (NOT linear) is
y(x) = -2*2^(x+1)
Check:
y(-1) = -2*2^(-1+1) = -2*1 = -2
y(0) = -2*2^(1) = -2*2 = -4
...
y(2) = -2*2^(2+1) = -2*8 = -16
all good.