If I have Y=-3X+21 do i simplify or keep it just the same???
What is the original problem? What does the problem state to do?
You could write this as,
y = 3(x + 7)
Depending on your problem y = 3x + 21 is acceptable, especially if you are learning slope-intercept form of an equation.
But you wouldn't be wrong to write this as, (if you are learning factoring).
y = 3(x + 7).
The equation Y = -3X + 21 appears to be in simplified form, called slope-intercept form. In this form, the coefficient of X (-3) represents the slope of the line, and the constant term (21) represents the Y-intercept. So, you do not need to simplify it any further.
To properly answer your question, we need to determine whether the equation Y = -3X + 21 can be simplified further or if it is already in its simplest form.
The equation provided is already in its simplest form, since it is written in slope-intercept form (Y = mx + b), where "m" represents the slope (-3 in this case) and "b" represents the y-intercept (21 in this case).
If you have any additional information or requirements, please let me know and I will be happy to assist you further.