Is 5x-y=-21 in slope intercept y=5x+21

Yes.

what is -4x+y=6,-5x-y=21

solving by Substitution

can u show the steps to get to one of those answers

To determine if the equation 5x - y = -21 is in slope-intercept form, we need to rearrange it to the form y = mx + b, where m represents the slope and b represents the y-intercept.

Let's start by isolating y on one side of the equation:

5x - y = -21

To move -y to the other side, we can add y to both sides:

5x = y - 21

Next, let's switch the sides so that y is on the left side:

y = 5x - 21

Now we have the equation in slope-intercept form, y = mx + b, where m = 5 (the slope) and b = -21 (the y-intercept). Therefore, the equation 5x - y = -21 is equivalent to y = 5x - 21 in slope-intercept form.