#### Answer

The equation would be B(t)=500×$2^{t}$
a)
The budget in 1 yr will be 1000
The budget in 2 yrs will be 2000
The budget in y years will be 500×$2^{y}$
b)
The budget 2 years ago was $125

#### Work Step by Step

The equation would be B(t)=500×$2^{t}$
a)
The budget in 1 yr
B(1)=500×$2^{1}$ = 500×2 = 1000
The budget in 2 yrs
B(1)=500×$2^{2}$ = 500×4 = 2000
The budget in y years will be 500×$2^{t}$
b)
The budget 2 years ago (t=-2)
B(-2)=500×$(2)^{-2}$ = $\frac{500}{2^{2}}$ = $\frac{500}{4} = $125