math homework help?

Question

i'll do my best to translate from japanese to english... but help

1. There is a two-digit number. The tenth number (the one on the left... for example in 10 it is 1) is 7. If you switch the tenth number and the ones number, the result would be a number 18 smaller than the original. What is the original number?

Answer 1

So it has to be 70-something.

Let the ones number be x, and then try to solve for x.

70 + x is the number.

If you switch it around you get 10x + 7. If you take 18 away from 70 + x you get this number.

70 + x - 18 = 10x + 7

52 = 10x + 7 - x

45 = 9x

x = 5

So the number is 75.

Answer 2

Let 70+a = first number,
10a+7 = second number

Their difference is 18, or:

70 + a - (10a + 7) = 18
63 - 9a = 18
9a = 45
a = 5

So your original number is 70+a = 75

(Notice this works, because your two numbers would be 75 and 57, and their difference is 18)

Hope that helped!

~ ♥ ~

Answer 3

let the number be 7x
value of the number=70+x
when you switch the no wll be x7
value now will be10 x+7
given
70+x=7+10x+18
9x=45
x=5
so the number is 75

Answer 4

64 reversed is 46 - 18 numbers between

hai ?

domo aragato