Answer: 1 is not a perfect square. 3 is the only prime number one less than a square.
X + 3 = 8
x = 8 - 3
x = 5 <=
The answer is five hundred sixty.
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
112
/ \
2 56
/ \
2 28
/ \
2 14
/ \
2 7
So, the answer is 2 x 2 x 2 x 7 or 2^3 x 7