Final answer:
The slope of the line represented by the equation y = -1x + 3 is -1, which is option (A). This is found by identifying the coefficient of x, which represents the slope in the slope-intercept form of a linear equation.
Step-by-step explanation:
In the equation y = -1x + 3, the slope of the line can be identified by looking at the coefficient of the x-term in the equation, which is written in the slope-intercept form (y = mx + b). In this case, it is -1. Therefore, the correct answer is (A) -1.
According to the slope-intercept form, 'm' represents the slope of the line and 'b' represents the y-intercept. The slope determines the angle and direction of the line on the graph. A negative slope indicates that the line goes downward as it moves from left to right, which matches choice (a) stating it is a straight line with a negative slope.