Posted: 2/1/2010 3:25:25 PM EDT
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Of course, I'm at the point of just going ballistic over this. I'm taking an online math quiz. It's repeatable but the problems change slightly. They're pretty much the exact same problems but with slightly different numbers. This is the 3rd time I've taken this quiz and I've gotten this one problem wrong. I don't know what I'm doing wrong. The question is:  I know what I got. I know what the quiz says is the right answer. I want to see if I'm insane or not. ETA: What a cluster fuck, one sec. |
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Quoted:
Of course, I'm at the point of just going ballistic over this. I'm taking an online math quiz. It's repeatable but the problems change slightly. They're pretty much the exact same problems but with slightly different numbers. This is the 3rd time I've taken this quiz and I've gotten this one problem wrong. I don't know what I'm doing wrong. The question is: 5x+6 2x+18
_____ MINUS ______ x-4 x-4 Answer and simplify. I know what I got. I know what the quiz says is the right answer. I want to see if I'm insane or not. ETA: What a cluster fuck, one sec. The parts in red, are we supposed to multiply or what? |
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(5x+6)/(x-4)-(2x+18)/(x-4)
since both fractions have the same denominator, you can just place the x-4 off to the side for right now. (5x+6)-(2x+18) or 5x+6-2x-18 (dont forget to put the minus sign on the 2x and the 8) so 5x-2x+6-18 so you get 3x-12. now put that back over the denominator and you get.. (3x-12)/(x-4) |
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Quoted: Now I get 3. Quoted: uhhh, I get 3x-12/x-4. Is this a trick question? Nope. That's what I get as well, except now it needs to be simplified. So, simplify it and tell me what you get. I forget the operation is but I expanded 3x-12/x-4 to 3(x-4)/x-4. Cancle the x-4's and you are left with 3. eta; saw you got it. It threw me off too. Let me guess, MyMathLab? |
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If you are unsure about any other problems try this site: http://www.intmath.com/Basic-algebra/Algebra-problem-solver.php |
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Quoted: Quoted: This. There is no FOIL in this problem. Denominators are the same so it's like any subtraction of fractions. Don't forget the implied parentheses and to distribute the negative.uhhh, I get 3x-12/x-4. Is this a trick question? No because you can factor out the (x-4). The answer is just 3. |
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Quoted: Quoted: Quoted: This. There is no FOIL in this problem. Denominators are the same so it's like any subtraction of fractions. Don't forget the implied parentheses and to distribute the negative.uhhh, I get 3x-12/x-4. Is this a trick question? No because you can factor out the (x-4). The answer is just 3. To be specific, the answer is 3 for all x!=4 |
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Quoted: Quoted: To be specific, the answer is 3 for all x!=4Quoted: No because you can factor out the (x-4). The answer is just 3.Quoted: This. There is no FOIL in this problem. Denominators are the same so it's like any subtraction of fractions. Don't forget the implied parentheses and to distribute the negative.uhhh, I get 3x-12/x-4. Is this a trick question? Stickler!  |
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Quoted: If you solve for X it comes out to an answer of 4. If you substitute 4 in the equation for the X, the denominator (lower number) which is X-4, you would have 4 minus 4 which equals zero. You can't divide by zero so the problem is unsolvable as stated. YOU FAIL AT THE MATH |
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If you solve for X it comes out to an answer of 4. If you substitute 4 in the equation for the X, the denominator (lower number) which is X-4, you would have 4 minus 4 which equals zero. You can't divide by zero so the problem is unsolvable as stated. There is no equation given |
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If you solve for X it comes out to an answer of 4. If you substitute 4 in the equation for the X, the denominator (lower number) which is X-4, you would have 4 minus 4 which equals zero. You can't divide by zero so the problem is unsolvable as stated. YOU FAIL AT THE MATH U B right. I missed the minus sign and thought it was an = sign. Just for fun, Solve it as if the minus WAS and = sign. |
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Quoted: Quoted: Yes you can. The same equation could be written 5x/x-4 + 6/x-4 - 2x/x-4 -18/x-4 Now sum, and then simplify.Quoted: You can't just separate those like that! Quoted: This.uhhh, I get 3x-12/x-4. Is this a trick question? 5x-2x= 3x, 6-18=-12  Yes, it can be written this way. It didn't look to me that you were preserving the denominators. ((5x/x-4) + (6/x-4)) - ((2x/x-4) + (18/x-4)) (3x/x-4) + (-12/x-4) = (3x-12/x-4) = 3(x-4)/x-4) = 3 |
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Yes you can. The same equation could be written 5x/x-4 + 6/x-4 - 2x/x-4 -18/x-4 Now sum, and then simplify.
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You can't just separate those like that! Quoted:
This.
uhhh, I get 3x-12/x-4. Is this a trick question? 5x-2x= 3x, 6-18=-12
Yes, it can be written this way. It didn't look to me that you were preserving the denominators. ((5x/x-4) + (6/x-4)) - ((2x/x-4) + (18/x-4)) (3x/x-4) + (-12/x-4) = (3x-12/x-4) = 3(x-4)/x-4) = 3 I was just ignoring them because they were common. 
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Quoted: Quoted: U B right. I missed the minus sign and thought it was an = sign.Quoted: YOU FAIL AT THE MATHIf you solve for X it comes out to an answer of 4. If you substitute 4 in the equation for the X, the denominator (lower number) which is X-4, you would have 4 minus 4 which equals zero. You can't divide by zero so the problem is unsolvable as stated. Just for fun, Solve it as if the minus WAS and = sign. If this is what you are describing then there is no solution. |
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This. I spent Friday and yesterday teaching this skill to 14 year olds. well, TRYING to. We had one problem come out to be 1 them "what!? how can that whole mess be ONE?" me "that's for me to know and you to LEARN!" Quoted: 3. the answer is 3. look at the numerator only. 5x+6-(2x+18)=5x+6-2x-18=3x-12=3(x-4). so 3(x-4)/(x-4) = 3. -GTDHW's wife |