In this question, letters stand for numbers.If A = 25, B = 3, C = 64, D = 2, E = 21,what is the answer to this sum written as a letter?C - D x E + B = [?]

First, we need to substitute the given values into the equation.

So, C - D x E + B becomes 64 - 2 x 21 + 3.

Next, we need to follow the order of operations, which is parentheses, exponents, multiplication and division (from left to right), addition and subtraction (from left to right). This is often remembered by the acronym PEMDAS.

There are no parentheses or exponents in this equation, so we move to multiplication: 2 x 21 = 42.

Now, substitute this value back into the equation: 64 - 42 + 3.

Then, perform the subtraction: 64 - 42 = 22.

Finally, add 3 to get: 22 + 3 = 25.

So, C - D x E + B = 25.

Looking at the original values given, 25 corresponds to the letter A.

So, the answer to the sum C - D x E + B is A.