I'll be honest, I don't pay attention in class because I know I'll just come home and watch The Academy's video. The bonus factor is that I will understand in under 15 minutes what my teacher struggles to explain in 50 minutes.
I want to cry, ive been studying this for hours and just couldnt get it (have a math test tomorrow). This video made me understand it all THANK YOU SO FUCKING MUCH
I wish they'd go through equations that didn't work so well. ike equations where you have to do a little more and it doesn't all just seamlessly fit together
I get it on here but look at my homework and go what is this. My homework is out of the prentice hall algebra 2 book and you can learn one thing sitting in a class where the problems are simple but get the homework and it’s like I don’t understand it.
My teacher does a horrible job explaining things, plus the fact that she just shows us what to do instead of how and why you do it, and on top of THAT it's hard for me to understand math quickly. This really helped. A 42 minute ill explained lesson compressed into a 13 minute well explained lesson
Thanks, this video was very helpful for me. Tomorrow I'll be taking my math exams and rational equations were one of them.. Thanks a lot Khan Academy!!!
He just simplified both sides of the equation. He had: 5/35 = 2/14. 5 divided by 35 = 1/7. 2 divided by 14 = 1/7. Since 1/7=1/7, that means that the value of "x" which he put in is the correct one and is a solution.
I've been struggling with this for so many hours, I have a quiz I need to asnwer due today and the way our teacher taught us in our online class, I didn't really understand. Thanks for the vid!!!
I learned that shit already in advance math but we never simplfied the square root... We left it as it was bc we werent allowed to use decimals unless it was a perfect square and 113 isnt a perfect square...
Is the... method of transforming rational algebraic equatiion to quadratic equation present .?? Right Thanks .....a lot... i owe you ..my presentatio and assignment ia pres...
But he's not explaining the quadratic formula in this video, therefore, he would just get through it fast. The explanation for solving rational equation was pretty detailed though.
I know this comment will go unseen here, but I'd feel guilty if I didn't thank Khan Academy for the full lesson they just taught me in less than a quarter of what my teacher would spend on the same topic. Thank you!
+Anonymous User Using the "quadratic formula" you can determin what X is equal to. So if you get a complicated question where your final quadratic cannot be used by factoring, you use the quadratic formula.
Hi, I have a question I'm struggle with for hours now. Why do we not multiply the denominator by the Least Common Factor too if we're solving the equation? But if we're simplifying an expression, dont we have to multiply both nominator and denominator by the LCF too?
Haha he turned the equation into a quadratic formula. It’s how you can solve quadratics and you can do it when you have an equation where the first term has an x and is squared, and second term with an x (not squared) and a regular number. When there are usually three terms like that, you can plug in the values (not including the x’s) into the quadratic formula to solve the quadratic.
at 4:25 I dont understand how you take x^2 + 2x -8 and factor it down to x+4 times x-2. I see were x+4 is because the power of two but i cant figure out how you get the x-2
Here's the explanation even though it's super late hahaha He factored the denominator x^2+(2)x+[8] ____+____=(2) ____•____=[8] ^ ^ 4 -2 So the factored form of x^2+2x-8 is (x+4)(x-2)
I don't know how fast you could respond to this question but in my college algebra 1 class I'm struggling to understand this equation with rational equations. It's x^2 - 10x + 25/ 3x-5
You can solve it in your head, but if you don't have a calculator you can leave the square root without solving it. You could also simplify the radical expression, unless its a perfect square root. Its weird that you're not allowed to use a calculator though
For the future people cramming their Algebra test (like me hehe) and scrolled down the comments section to ask where the hell the square root came from, it's because he used the quadratic formula to factor the equation. And you SHOULD know what the quadratic formula is, since you should've learned that from solving quadratic equations.
I'm confused as to how you were able to rewrite x^2+2x-8 into x+4*x-2. I know it is possible, but I don't know how you did it. If someone could explain this, that would be great (: @4:26
Hey, I know am 3 years late but there may be others with the same question as you so here I'll simplify it step by step. Step 1: AC Method The quadratic x^2+2x-8 is in the form ax^2+bx+c. This will work for any trinomial. It's called the AC Method because we multiply A and C, which in this case is 1 (because the coefficient of x^2 is 1) and -8 and we get -8. Step 2: Factoring Now that we have the number -8, we have to find a pair of numbers that when multiplied will equal C (-8) and when added will equal B (2). You can go ahead and list the factors, like 1 and -8 is a pair, or -4 and 2. Once you get the hang of it, you can quickly factor in your head. He saw that 4 and -2 multiply to get -8 and add to get 2, which is why he ended up with turning that into (x+4)(x-2). Hope this helps :)
@@jah-4 Haha, well thanks anyways! I'm sure it helped others. 3 years later, I can look at the equation and figure it out now, so I guess I am testament to the success of the schooling system.
