The answer is 9, hope this helped <3
B. ) Unless you're missing some data.
Width=1cm and length=21cm or width=3cm and length=7cm.
The equation seems to be
1
-------- = 5 ^ (x + 4)
25
In that case, this is the solution, stept by step:
1) factor 25: 25 = 5^2
1
=> ----------- = 5^(x + 4)
5^2
2) invert 5^2
=> 5^(-2) = 5^(x+4)
3) Given that the bases are equal, the exponents also have to be equal:
=> - 2 = x + 4
3) transpose +4:
=> - 2 - 4 = x
=> x = - 6
Answer: - 6
