How do you solve 3r + 3 = 6r - 9 ?
There will be a few steps you will need to take. Heres my example I will use. I just made it up.
6X + 3 = 12X - 15
First objective is to get the X's on to one side. You accomplish this by doing the opposite. There is a posative 6X so subtract 6X.
Keep in mind what you do to one side of the equals sign you MUST do to the other so....Subtract 6X from BOTH sides.
Here is how it will look....
6X + 3 = 12 X - 15 Orginal equaiton
-6X + 6X + 3 = -6X + 12 X -15 -6X both sides. Now combine like terms both sides.
You should have:
3 = 6X - 15
(-6X + 6X) = 0 Left with 3
(-6X + 12X) = 6X When multiplying add numbers leave X
3 = 6X - 15 We want X by itself. 15 is in the way! We have -15 Once again we do the opposite. The opposite of subtraction is addition...ADD 15 to BOTH sides. Remember what you do to one side you MUST do to the other. So...
15 + 3 = 6X -15 + 15 ADD 15 to both sides. Combine like terms.
18 = 6X This is what you should have.
(15 + 3) = 18
(-15 + 15) = 0 Cancel them OUT!
We have 18 = 6X
Be careful...
6 is WITH the X which means 6 times X. The opposite of multiplication is... DIVISION.
You want X by itself so DIVIDE BOTH SIDES by 6.
18 / 6 = 6X / 6 In division the 6 in 6X AND the denominator 6 CANCEL. (Cross these out)
18 / 6 = X Or the correct way...
X = 18 / 6 Solve. 18 / 6 = 3 Therfore, X =3.
CHECK
6X + 3 = 12X - 15 Original equaiton.
6 (3) + 3 = 12 (3) - 15 Put in 3 for X. We just solved this.
18 + 3 = 36 -15
21 = 21 LUCKY 21!