+2.15.
Explanation: subtract 6.3 by 4.15 = 2.15 so you add 2.15
Answer:
I think -3.5 is the right answer
The length of line in green = 5 cm
the length of line in yellow = 3 cm
the length of line in red = 6 cm
the length of line in white = 16 cm
the total area = 100 + 12 + 12 + 20 + 24 + 96 = 264 cm2
We will write it as a fraction in ordet to solve, that is:

We then operate as follows:

We have this, since 1 integer will be equal as a numerator divided by a denominator with equal values. Examples 1 = 2/2, 1 = 45/45, ...
The answers are A and D.
The numbers that you cannot simplify without having a radical in the answer are irrational numbers.
√(4/16) = 1/4 or -1/4, rational number
√(9/16) = 3/4 or -3/4, rational number
√(9/4) = 3/2 or -3/2, rational number
√(3/16) = √(3)/4, NOT a rational number, cannot remove radical
√(3/4) = √(3)/2, NOT a rational number, cannot remove radical