Isolating 2 veriables

how do you do it? o.o I NEED to know tonight, i have a test tomorrow. Can someone help?

whats the question?

I don't have a specific question, i need help in general x_x

give me an example so i can show you

what class is this? Algebra?

Yeah it is.

hmmmm.... even though i already did the test, i still don't get it >.<

Here:

In a grade 6 class, theirs 33 students. There are 9 more girls then boys. How many boys and girls are in the class?

Easy.
33 minus 9 equals 24
Divide by 2.
12 plus 9
12 boys and 21 girls.

oh thats simple. just set up the equasion. and solve for it.

Heres how you should set up and solve your equation.

33 (# of kids in class) = X (X will represent boys in class) + (x+9)
Simplify
33 = 2X + 9
subtract 9 from both sides.
24 = 2X
divide both sides by 2
12 = X
Therefore there are 12 boys and since there are 9 more girls than boys there are 21 girls. Add them together and they equal 33. That's your answer, 12 boys and 21 girls.

o.o WOW that is so different then what I got:


I got 24 boys, and 33 girls o.o

I know what you did wrong. You set up the equation as:

33 = x+9

However that's incorrect, that's basically saying that x (this will represent the # of boys) + 9 girls/boys will equal 33. That's not right. The correct equation is this:

33 = x+ (x+9)

See the difference? You have to account for both variables, x and x+9. X representing the amount of boys and x+9 representing the amount of girls. It's x+9 because if we choose to use x as our variable for the amount of boys, and the problem states that there are 9 more girls than there are boys, you have to add a +9 to the x. Any more questions?

Wow I'm in Algebra 1 now and we haven't done anything liek this....



>_>

ch4rg3rs4lyf wrote:

I know what you did wrong. You set up the equation as:

33 = x+9

However that's incorrect, that's basically saying that x (this will represent the # of boys) + 9 girls/boys will equal 33. That's not right. The correct equation is this:

33 = x+ (x+9)

See the difference? You have to account for both variables, x and x+9. X representing the amount of boys and x+9 representing the amount of girls. It's x+9 because if we choose to use x as our variable for the amount of boys, and the problem states that there are 9 more girls than there are boys, you have to add a +9 to the x. Any more questions?

Actually, I did x + 9 - 9 + x = 33 - 9 = 24 + 9 = 33

24 boys and 33 girls o.o

There are 33 students. Not 57. Unless they all had underage sex and had 24 babies.

I consider myself a math nerd...

This is an old topic.
And Eli, I'm in calc >_>

Damn , my exams are coming up (like most people) and I'm starting with Math .
I'm doing Science With the option of 6 houres of math and it's a damn hard exam .
I know most of you don't care about this but it's pretty hard .

why are we keeping this topic alive? somebody ask for more help :(

Steven, you can't even use The Pythagorean Theorem To solve for c, so gtfo with that calc crap.

RagingChadzi wrote:

Steven, you can't even use The Pythagorean Theorem To solve for c, so gtfo with that calc crap.

Lol my ass I can't.

Ewww. I hate math. I'm more of a language person myself.