1. ## Simaltaneous Equation Question

Hi I'm studying for my A-levels and I came across this question and it just stumped me (pic attached), why does one divide the (y^2/12) by 4, I can't seem to work it out. Any explanation/Help would be greatly appreciated

2. ## Re: Simaltaneous Equation Question

Originally Posted by hellomynamesbruce

Hi I'm studying for my A-levels and I came across this question and it just stumped me (pic attached), why does one divide the (y^2/12) by 4, I can't seem to work it out. Any explanation/Help would be greatly appreciated
One doesn't. Where did you get the idea that one divides by 4? One equation says that 3y= 4x+ 6 which says that x is multiplied by 4. The other equation gives $x= y^2/12$ so 4 times x is $y^2/12$ multiplied by 4.

3. ## Re: Simaltaneous Equation Question

Yeah but if you look from the second line to the third the equation has gone from 3y= 4(y^2/12)+6 to 3y= (y^2/3)+6 so the 3 has been divided by four. That's what I'm confused by sorry for not making that clear.

4. ## Re: Simaltaneous Equation Question

Originally Posted by hellomynamesbruce
Yeah but if you look from the second line to the third the equation has gone from 3y= 4(y^2/12)+6 to 3y= (y^2/3)+6 so the 3 has been divided by four. That's what I'm confused by sorry for not making that clear.
No, it hasn't. In the first place, the only "3" in the first equation is on the left and it is still there in the second equation. No three has been divided by 4. 1/12 has been multiplied by 4, as I said before. Since 12= 3(4), 4/12= 1/3. That's where the "y^2/3" on the right comes from.