Final answer:
The order of the functions from the least steep slope to the steepest slope is: c, d, b, a.
Step-by-step explanation:
The steepest slope of the functions can be determined by looking at the coefficients of the x-terms. The greater the coefficient, the steeper the slope. Now let's analyze the given options:
a. y = 4x + 0.5: The coefficient of x is 4, so this function has the steepest slope.
b. y = -2x + 3: The coefficient of x is -2, so this function has a steep slope, but it is less steep than function a.
c. 4.2: This is a constant function, which means it has a slope of 0. It has the least steep slope among the given options.
d. y = -0.5x + 7: The coefficient of x is -0.5, so this function has a moderate slope, steeper than function c but less steep than function b.
Therefore, the order of the functions from the least steep slope to the steepest slope is: c, d, b, a.