Answers

2015-11-26T15:37:55+08:00
The answer is number 10 because you can add 3 to 10
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wrong! UNDERSTAND THE PROBLEM PLEASE..
2 DIGIT NUMBER!! IT CANT BE 13 ... THE TENS IS 3 MORE THAN ONES DIGIT!! PLEASE UNDERSTAND IT!!
it cant be 10 I mean
2015-11-26T18:14:40+08:00
Let x= ones digit
x+3= tens digit

Equation:
x+x+3=13
combine them
2x+3=13
2x+3-3=13-3
2x=10
2x ÷ 2=10÷2

x=5
x+3=8
the answer is 85
8+5=13

To understand algebraic expression...
whatever you do in the left side or right side... you must do it on the other side
The answers can be negative!! IT DEPENDS
Don't worry just trust me :P and when you're grade 6/7 this will be tough on you as soon as possible XD just trust me ;)

You can do gues and check lol (just realize it after a couple of minutes )
Guess of two one-digit numbers that their sum is 13
9,4
8,5
7,6
then one number must be 3 greater than the other which is 8 and 5
SO... 85
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