The sum of two numbers is 188 and the difference is 34. What are the numbers? 

That’s ow I did it in my head also

I did it similarly dividing 188 by 2 to get 94, then dividing 34 by 2 and subtracting that from one of my 94s and adding it to the other. Your way is easier.

Beware in some exams there are marks for method so may well be wanting variable like x. Would depend on the exam.

I did the exact same method. Easy peasy

That's so helpful more than video

Yah that is what I did.

I'm glad I saw this reply...I was about ready to post the same thing! To prove you're right, 111+77=188. 111-77=34. If you're like me, it took only as many seconds to figure this out, as the number of minutes this video took to explain it!😎😎

I went that way too.

The same. Cool.that’s away of a thinking brain

Sheesh...an example of making an easy solution hard..

Nice mathematical reasoning!

Same. Kind of brute the answer. It worked for this one.

Same

its far easier to just add 188 + 34 = 222 and then divide by 2 to get 111, which is the first number. For the other number you can either subtract 34 and you get 77 or you subtract the 111 from 188 to get 77.

The goal is to find the answer using the tool of algebra, your limitless powers put aside.

@@marcreider9573mine is using algebra, just a shortened form of it. x + y = 188 x - y = 34 add both equations and you get 2x = 222 |:2 x = 111 then use that in one of the first equations to get the value of y = 77.

You know what you're doing, which is good. You're still working with two variables, but you've processed one of them in your head, rather than on paper. That makes it less easy for someone else to follow along. Better, I think, to be verbose and take small steps, rather than leaps. Showing where the (X+34) came from would add clarity. You could start with the second equation and transpose so that y is isolated on the left side. Then show the substitution into the first equation. Also, this part has combining terms, subtracting from both sides, and the result of that subtraction, all occurring in one step: X + (X + 34) = 188. 2X = 188-34. In my opinion, they should be done in separate steps so others can more clearly see what you're doing. -------------------------------------------- [Difference] Y - X = 34 Y - X + X = 34 + X Y = 34 + X Y = X + 34 ------------ (We'll use this now and at the end.) [Sum] X + Y = 188 (substitute) X + (X + 34) = 188. 2X + 34 = 188 2X + 34 - 34 = 188 - 34 2X = 154 X = 77

Excellent explanation. I had a page of scribbled equations as I floundered around. Your solution revived my flagging brain in seconds! 👍

​@retread1083 How about? X + Y = 188 X - Y = 34 Add the two equations to get 2 × X = 222 X = 222 / 2 = 111 Y = X - 34 = 111 - 34 = 77

@@dougnettleton5326 That certainly gets to the correct values but if you don't mind, I'll offer some suggestions to improve your presentation. I think it adds clarity if you start a new line for each change, so I'd avoid stringing equalities across the same line. You could add a line when you solve for X to literally show the addition before actually performing the addition. X + Y = 188 X - Y = 34 Add the two equations to get X + Y + X - Y = 188 + 34

​@retread1083 Very funny😂 My original solution was: X + Y = 188 X - Y = 34 Add to eliminate Y 2X = 222 X = 111 Y = 111 - 34 = 77 The deleted stuff was added for clarity. I had a line at the end "No need to write a book" but deleted it. I don't think anyone needing the painful level of detail you provided would be able to work a device where they would encounter the video with the problem.

I took a different route. I subtracted 34 from 188, leaving 154. Then I divided 154 by 2, giving me 77. Then I added the 34 to 77 to give me the other number, 111. The algebraic equation I used was X + 34 + X = 188, or 2X + 34 = 188, or 2X = 154, or X = 77, and X + 34 = 111.

Hey, whatever works for you. If everyone thought and processed things the same way, it'd be a boring world.@@TheHawk--oe8iq

Systems Of Equations

Yes, a simple and very logical way to do it in one's head ...it takes about twelve seconds or less.

That is what I did right off the get go . Takes seconds to figure it out .

I did it this way also. Solved mentally in just a few seconds and didn't need a calculator OR algebra.

I did it similar, I halved 188 and 34 and got 94 and 17, then I added and subtracted 17 from 94.

​@@eddyrourke5514That's exactly the method I used in my head in well less than a minute.

I only took math to Grade 12. I have forgotten most of it. This is a good review but is a bit Greek to me.

I like this explanation, as well.

Same here. 😅

I've gotten into the habit of trying to solve the problem from the thumbnail, then opening the video and using the scrubber to skip to the solution. If I'm right, I don't watch the video unless I I think it might show me a better way of solving the problem; if I'm wrong, however, then I watch pretty much the whole video.

This is the method I used.

Yup. Solve two equations. Old way, but works very well. 😀@@sonyacotton4881

Exactly how I solved it.....

That's the substitution method he briefly mentioned at 12:35 But you've skipped steps to get there.

That’s basically how I solved it, no pencil needed lol. Yes still used a calculator.

That's how i solved, but in my head in a few seconds.

Yes that is how I solve it until he reminded me to use algebra then I used the substitution method. Not elimination like he did.😁

Exactly how I did it. But I did use a calculator.

Hi. Can you explain why you cut each number in half? I used substitution method but I would love to understand what you did. Thanks!

Remember he is pitching these lessons to people who maybe NEED more explanation than you.