With the if and switch statements to achieve the following calculation respectively, the value of a, b, c, x from the keyboard input：

Sure, in MATLAB, you can use both `if` and `switch` statements to perform calculations based on user inputs for variables `a`, `b`, `c`, and `x`. Here's an explanation and examples of how you can implement each:

**Using an if statement:**

If you have a fixed number of conditions to check (like different arithmetic operations), you can use multiple `if` statements with `else` clauses:

% Prompt the user for input
a = input('Enter value for a: ');
b = input('Enter value for b: ');
c = input('Enter value for c: ');
x = input('Enter value for x: ');

% Perform calculation based on input
if isnumeric(a) && isnumeric(b)
    % If a and b are numbers, perform some operation
    result_if = a + b;
else
    disp('Invalid input. Please enter numerical values.');
end

if isnumeric(c) && isnumeric(x)
    % If c and x are numbers, perform another operation
    result_elif = c * x;
else
    disp('Invalid input. Please enter numerical values.');
end

This code will calculate the sum or product depending on which inputs are provided.

**Using a switch statement:**

Switch statements allow you to compare a variable against a series of cases:

% Similar to above
a = input('Enter value for a: ');
b = input('Enter value for b: ');
c = input('Enter value for c: ');
x = input('Enter value for x: ');

switch true
    case isnumeric(a) && isnumeric(b)
        result_switch = a + b;
    case isnumeric(c) && isnumeric(x)
        result_switch = c * x;
    otherwise
        disp('Invalid input. Please enter numerical values.');
end

In this case, it checks the conditions and executes the corresponding block of code.

Keep in mind that if there are many possible operations or conditions, using a combination of `if` and `elseif` may be more appropriate than just `switch`.