Ok so look for the change between x and y.
X-doubling periods
Y-height of bamboo
Y=ab^x
1) make a table of values
X Y
1 5
2 10
3 20
2) write equations and substitute
5=ab^1 —> a=5/b^1 —> a=5/b
10=ab^2
Substitute into second equation
10=(5/b)*b^2
10=5b^2/b
10=5b
b=2
Substitute back in
b=2
10=a*2^2
10=4a
a=5/2
End equation:
Y=5/2*2^x
Answer:
A is a subset of B i believe that's the answer
If I'm correct you, add the two prices together, getting the price of $429.99