?
Lv 5
? asked in Science & MathematicsMathematics · 8 years ago

Two step equations. I have no idea how to do them. I read the lesson 2,00,000 (no really, been reading it everyday for weeks) and I just cannot understand it. I"ve tried so hard I don't get it at all! Please help, an example problem is

4m + 7 = 3

By the way i'm 13 , im in 8th gradebut im really behind and im doing 7th grade math. If you give me the answer can you explain how you got it?? Thanks !

Relevance
• 8 years ago

4m + 7 = 3

4m + 7 - 7 = 3 - 7 ... Subtract 7 on both sides

4m = -4

4m/4 = -4/4.... Divide 4 on both sides

m = -1

you want to get m by itself

- "m" on one side of the "equals" sign, and some number on the other side.

• 8 years ago

Ok so the question is

4m + 7 = 3

You want to solve for "m" the missing variable. The variable just represents some number that makes the equation balanced (both sides are the same)

Step one is to isolate the m so what's the easiest thing you could do?

The +7 has nothing to do with m so simply subtract it from both sides

4m + 7 (-7) = 3 (-7)

4m. = -4

See how the seven went away?

Now what do you do to isolate the m? Well it says 4m so that means 4*m or 4 times m. So what's the opposite of multiplication?

Division

So devide both sides by 4

4m /4 = -4/4

m. = -1

There you go :)

You should watch patrickJMT on youtube he's the best there is at explaining things. Best regards

• 8 years ago

When solving such Algebra questions, the first thing to do is to put all the numbers on one side and all the lettered numbers on the other side.

So for 4m + 7 = 3, we have to move 7 to the Right hand side of the equal sign (=). So we subtract 7 from both sides

4m + 7 - 7 = 3 - 7

Since 7 - 7 = 0, we get

4m = 3 - 7

Now 3 - 7 = - 4, so we are left with

4m = - 4

We divide both sides by 4 so that we are left with only "m" on the Left Hand Side

4m/4 = -4/4

m = - 1

• Anonymous
8 years ago

You want to get the variable "m" to stand alone this is a multistep process easy too first the way to go is subtract 7 from the numbers without the variable so subtract the 7 from the 7 and 3 and you got 4m= -4 (3-7=-4). Now comes the Division step now that you got the 4m =-4 so divide 4 from both sides 4m divided by four equals 1m and -4 divide 4 equals -1 now substitute the -1 for m and add it to the equation 4 X -1 equals -4 and add 7 and comes to 3. So M =-1

• 8 years ago

Our goal is to isolate m, but seeing m is attached to 4, our first goal is to isolate 4m. We do this by subtracting 7 from both sides.

4m+7-7=3-7

4m+0=-4

4m=-4

Now we can isolate m by dividing 4 on both sides.

(4m)/4=-4/4

m=-1

Maybe sit down with your teacher and tell them that you really are trying hard, but you don't understand this math. I had a few great math teachers in high school who would stay after school everyday for half an hour or longer waiting for students to ask for help while they marked papers. They could've marked papers at home, but just in case you needed extra help, they would stay. I found it strange that no one would go to their classrooms except for me, and take advantage of their free help. Really, 10 minutes once or twice a week allowed me to graduate with a pretty high mark.

Sorry for rambling, but I know where your frustration comes from. Don't forget to ask older students that you may know.

• 8 years ago

Basically, you're trying to isolate the "variable" (in this case, m) on one side of the equals sign, and numbers on the other.

To do this, you can add, multiply, subtract, etc, etc … but WHATEVER YOU DO TO ONE SIDE OF THE EQUATION, YOU MUST DO TO THE OTHER.

Later on you'll learn some shortcuts, but if you stick to this rule for now, you'll be fine! :)

––––––––––––––––––

So, subtract 7 from both sides:

4m = -4

Divide both sides by 4:

m = -1

––––––––––––––––––

Check: 4m + 7 = 3

4(-1) + 7 = 3

-4 + 7 = 3 … true.

––––––––––––––––––

I've got a great website bookmarked … I'll get back to you.

Here. It starts at the very beginning. http://www.mathsisfun.com/algebra/definitions.html

Good luck!

––––––––––––––––––