Algebra

[nh10]

Hi,

My brother is doing algebra.

He needs to solve

4m = 12

Can someone who is good at maths, confirm that my methodology is correct as he doesn't believe me.

As to make 4m just m on it's own you need to divide by 4 so you also need to divide 12 by 4

 

[mmm4444bot]

Hi. Your reasoning is very good and your answer is correct, but your work shows that you subtracted four from each side, instead of dividing.

If your brother knows his multiplication table, another way to convince him (with such a simple equation) is to say that 4m is a product. It's the product we get when we multiply 4 by some number. If we want the product to be 12, then we ask ourselves, "What number do we multiply by 4 in order to get 12?"

In other words, 4 times what equals 12?

Cheers :cool:

 

[JeffM]

Hi,

My brother is doing algebra.

He needs to solve

4m = 12

Can someone who is good at maths, confirm that my methodology is correct as he doesn't believe me.

As to make 4m just m on it's own you need to divide by 4 so you also need to divide 12 by 4

View attachment 10580

EDIT: Dr. P has observed that those are not minus signs, but division signs. In that case, your reasoning is fine.

 

[Dr.Peterson]

Looking carefully at the image, I see that those ARE divisions; the dots are just very hard to see. So your work is correct.

We commonly write the work using a fraction bar on each side, with the 4 under it, rather than the obelus (division sign), possibly for this reason. Multiplying by 1/4 is also a good idea.

 

[Denis]

if u*a = v
then a = v/u

* = multiplication
/ = division

 

[Steven G]

if u*a = v
then a = v/u

* = multiplication
/ = division

And u=v/a !

 

[Steven G]

Hi,

My brother is doing algebra.

He needs to solve

4m = 12

Can someone who is good at maths, confirm that my methodology is correct as he doesn't believe me.

As to make 4m just m on it's own you need to divide by 4 so you also need to divide 12 by 4

View attachment 10580

I agree with mbot. Know what the question is asking! It is asking a very simple question, 4 times what equals 12. Since 4 times 3 equal 12, we conclude that m=3.