Solve for y
-3x + 3y = 21

y = x + 7

Step-by-step explanation:

Your equation is -3x + 3y = 21

You want to get the y by itself (this would be easiest if you kept the y on the left side of the equation since this is where the y formally is). To do this, you need to get the -3x on the other side. Since the integer is negative, you are going to add the integer on both sides (this will cancel out the -3x on the left side since you are doing the opposite of the integer). This is shown below.

-3x + 3y = 21

+3x           +3x

3y = 3x + 21

The part on the question on the right side is 3x + 21. The 3x is shown first because the x of these equations are always first. The 21 is + 21 because the 21 is already positive.

Now, we need to get the 3y to be y by itself. To do this, we need to divide the equation it total by 3. Since the 3 is attached to the y, this represents multiplication. You always want to do the opposite to do these equations. This step is shown below.

3y = 3x + 21

     /3

3y divided by 3 = y

3x divided by 3 = x

21 divided by 3 = 7

Now plug these into the equation.

y = x + 7

I hope this helps! Have a good day, and please mark brainliest ^-^

range is infinite on both x and y axis positive and negative

step-by-step explanation: