Identify the function to differentiate: The given function is -5x, where x is treated as a constant with respect to t.
Recall the rule for differentiating constants: The derivative of a constant multiplied by a variable is the constant itself multiplied by the derivative of the variable.
Since x is treated as a constant with respect to t, its derivative with respect to t is 0. Therefore, the derivative of -5x with respect to t is -5 multiplied by 0.
Simplify the expression: -5 * 0 results in 0.
Conclude that the derivative of -5x with respect to t is 0.