The interest rate is 3.5%.
EXPLANATION
We substitute the given values into the formula;

to obtain

We divide through by 6000 to obtain,

This implies that,

We take the square root of both sides,

This gives us,

Add -1 to both sides of the equation to obtain

Multiply through by 100 to obtain;

%
f) 16 - p = 12 minus 12
4 - p = 0 plus p
p = 4
g) 18 - 2p = 6 divide by -2
-9 + p = -3 plus 9
p = 6
h) p x 2 + 4 = 9 divided by 2
p + 2 = 4.5 minus 2
p = 2.5
i) p x 4 - 3 = 1 plus 3
p x 4 = 4 divided by 4
p = 1
You have to multiple and then add to get
(5)(-8)+(7)(2)=-26
A.125
Because to get from 5 to 25 you need to multiply by 5 so 25 times five equals 125