NationStates Jolt Archive

Okay, I'm working on an astronomy lab, determining a stars distance and whatnot using illumination and flux and that other fun stuff, and suddenly I find myself completely unable to remember how to do one of the most basic math actitivites: Move a number from one side of the "equal" sign to the other.

It's what you do when one or more numbers is a variable, you shift it around to get it on the other side of the "equal" sign so you can determine what that variable is equal to. When it's an addition, subtraction, or multiplication problem this is all pretty easy; you just subtract, add, or divide both sides of the equation by the number you wish to move. But, for some reason, how to shift a number that it is in a division problem is just not there. It's embaressing, last semester I was actually working as a math tutor, but I just can not remember.

Does anybody else remember?

Oh, and so people have a more clear understanding of what I'm talking about, this is the kind of equation I mean.

15/X= 2 + 3

Now, I do know that X = 3, but for the life of me I can not figure out how to move the 15 to the other side of the equation, so it reads X = 15/(2+3)

multiply by x on both sides.

multiply by 1/(2+3) on both sides.

15/X = 2 +3 -> X = 15/(2+3)

There you go.

Multiply by 1/15 for both sides?

Okay, I'm working on an astronomy lab, determining a stars distance and whatnot using illumination and flux and that other fun stuff, and suddenly I find myself completely unable to remember how to do one of the most basic math actitivites: Move a number from one side of the "equal" sign to the other.

It's what you do when one or more numbers is a variable, you shift it around to get it on the other side of the "equal" sign so you can determine what that variable is equal to. When it's an addition, subtraction, or multiplication problem this is all pretty easy; you just subtract, add, or divide both sides of the equation by the number you wish to move. But, for some reason, how to shift a number that it is in a division problem is just not there. It's embaressing, last semester I was actually working as a math tutor, but I just can not remember.

Does anybody else remember?

Oh, and so people have a more clear understanding of what I'm talking about, this is the kind of equation I mean.

15/X= 2 + 3

Now, I do know that X = 3, but for the life of me I can not figure out how to move the 15 to the other side of the equation, so it reads X = 15/(2+3)


Don't move the 15. Move the X. :)

Okay, I'm working on an astronomy lab, determining a stars distance and whatnot using illumination and flux and that other fun stuff, and suddenly I find myself completely unable to remember how to do one of the most basic math actitivites: Move a number from one side of the "equal" sing to the other.

It's what you do when one or more numbers is a variable, you shift it around to get it on the other side of the "equal" sign so you can determine that that variable is equal to. When it's an addition, subtraction, or multiplication problem this is all pretty easy; you just subtract, add, or divide both sides of the equation by the number you wish to move. But, for some reason, how to shift a number that it is in a division problem is just not there. It's embaressing, last semester I was actually working as a math tutor, but I just can not remember.

Does anybody else remember?

Oh, and so people have a more clear understanding of what I'm talking about, this is the kind of equation I mean.

15/X= 2 + 3

Now, I do know that X = 3, but for the life of me I can not figure out how to out the 15 on the other side of the equation, so it reads X = 15/(2+3)
Multiply by X on both sides. Divide by (2+3) on both sides. Go review your basic rules Associative, distributive, and commutative. Throw away the copy of mathcad, matlab, or mathematica that you have become dependent on.

going back to middle school, when I learned algebra, my education completely failed to show me how to do this. It wasn't until precalculus that someone showed me how to do it, in 10th. (Which is strange, seeing as how I managed straight A's in math.)

OK...

15/x = 2+3

15/x = 5

15 = 5x

15/5 = x

3 = x.

15/X= 2 + 3

Multiply by X

15 = x(2+3)

Divide with 2+3

x= 15/(2+3)

Pfft, who needs math for science?

going back to middle school, when I learned algebra, my education completely failed to show me how to do this. It wasn't until precalculus that someone showed me how to do it, in 10th. (Which is strange, seeing as how I managed straight A's in math.)

OK...

15/x = 2+3

15/x = 5

15 = 5x

15/5 = x

3 = x.

You know, it was basically the same thing for me. We never learned to do it properly 'til the ninth grade. Before that we always got so easy equations so no one bothered to do it the way it should have been done. I sure got problems later when the equations got harder. No it goes pretty much automatically for me.

Pfft, who needs math for science?
Who needs science when you have math?

i can barely count, let alone do sums.

Who needs science when you have math?

Who needs math when you have computers?

Who needs math when you have computers?
Who needs computers when you have NSG... oh wait.

Seriously though, I have the same problem. Since I learned how to program I've forgotten about math. I use an interactive Python shell as my calculator and to count the sum of all numbers from 1 to 50 my first idea is "sum(range(51))" rather then "50*51/2". Sometimes I even write Python functions to do stuff that would be quicker to do with math.

i can barely count, let alone do sums.

Same here, which is why I do language instead.

lawl. Who waits for the teacher to get around to it?