Question

Your teacher asks you to write a linear equation for a function in which the rate of change is -7 and the initial value is -2. You wrote the equation y= -7x + (-2). Your classmate wrote the equation y= -7x- 2. Another classmate wrote the equation y = (-2) + (-7)x. Your teacher wrote the equation y=-2 - 7x. Who is correct? Justify your response.​

Answer 1

y = = -7x + (-2), y = -2 - 7x are both correct

Explanation:

"rate of change" here refers to the "slope" of the line corresponding to the linear function. Thus, m = -7, and we know that the initial value (y-intercept) is -2. Thus, the desired equation is y = -7x - 2. YOU were correct, since YOUR y = -7x + (-2) is the same as y = -7x -2. However, what the teacher wrote was also correct: y = -2 - 7x.