The simplest way is to look at it algebraically.
So, suppose you start with a number. Let's call it N.
Step 1: You times it by 2. So N becomes 2*N or 2N.
Step 2: You add 10. So 2N becomes 2N + 10
Step 3: You divide by 2: So 2N + 10 becomes ("N+10)/2 which is N + 5
Step 4: You subtract the original number: So the N+5 becomes N+5-N, or 5.
Hope that's proved it for you.
the number was 340
You will get a positive integer. If you subtract a negative number, you will be adding it. I think of it like 2 minuses equals a plus. :P
i don't think that's possible because when you add 5 to a number, it gets bigger, but when you divide a number, its always a lower number. Unless there is actually a number you can do that with but i doubt it. hey, actually, it is possible. just make an equation: 5x=5+x. you're trying to solve for x right, so subtract x from both sides. you have: 5x-x=5, the same as 4x=5. then divide both sides by five to get x=5/4. (five-fourths) yeah that's right, were smart xD
Oh, dude, subtracting a negative number is like canceling out a double negative in grammar - it's a good thing! When you subtract a negative number, you're basically adding its positive counterpart. So, if you have -3 and you want to subtract it, just think of it as adding 3 instead. Easy peasy!
Think of it this way...how many times can you divide a number by itself? The answer is always once. 4 divided by 4 equals 1. Using the number 4, 8 divided by 4 equals 2. In other words, 8 is equal to two 4s, right? But one 4 is always one 4.
94 i think
I like this one.... think of a number multiply by 2 add 12 subtract 4 divide by 2 subtract the number you thought of and the answer is 4 it always works its a mathematical certainty once you have the number 4 you can add subtract etc to your hearts content and make any new number provided you remember the answer yourself.
always a negative number. just think about going backwards on a number line.
Call the unknown number n. Then, from the problem statement, {4[(n + 7 - 2) - n]} - 2 = 18. This is always true because [(n + 7 - 2) - n] is simply 5.
the number was 340
You can make lots of equations that have the solution 21. Here is one:x = 21If you think that is too trivial, add, subtract, multiply, or divide the same number to or from both sides.
think it 63
I think you divide the number of how many people are there there and divide it by 4....i think
Think about it like this. 0+x would equal x+0 but if you did the opposite then the answer would still equal x+0 because 'x' is an indefinite number and if you times, divide, subtract or plus then it would still equal x+0 or x-0 or x*0 or x divide 0.
You will get a positive integer. If you subtract a negative number, you will be adding it. I think of it like 2 minuses equals a plus. :P
i don't think that's possible because when you add 5 to a number, it gets bigger, but when you divide a number, its always a lower number. Unless there is actually a number you can do that with but i doubt it. hey, actually, it is possible. just make an equation: 5x=5+x. you're trying to solve for x right, so subtract x from both sides. you have: 5x-x=5, the same as 4x=5. then divide both sides by five to get x=5/4. (five-fourths) yeah that's right, were smart xD
By using the inverse function - inverse operations in the reverse order. If you are asked to think of a number, (A) multiply by 7, and (B) add 5, the person "reading your mind" will start with your answer and (B-1) subtract 5, and (A-1) divide by 7. Sometimes some of these are built into the process so that the "quizzer" has less to do.