Simultaneous Equations Question (1 Viewer)

[matchalolz]

A certain integer is between 10 and 100. Its value is 8 times the sum of its digits and if it is reduced by 45, its digits are reversed. Find the integer.

So far I have:
8(x+y) = xy
xy - 45 = yx

however i don't think this is right because when i wrote xy i meant it as two digits next to each other but then xy is usually x multiplied by y.

anyone know how to do this?? thanks

 

[Carrotsticks]

A certain integer is between 10 and 100. Its value is 8 times the sum of its digits and if it is reduced by 45, its digits are reversed. Find the integer.

So far I have:
8(x+y) = xy
xy - 45 = yx

however i don't think this is right because when i wrote xy i meant it as two digits next to each other but then xy is usually x multiplied by y.

anyone know how to do this?? thanks

Let the integer be 10x + y, where x is the first digit and y is the second digit.

So your first expression is incorrect. It should be 8(x+y) = 10x + y.

Second expression should be 10x+y-45 = 10y+x.

 

[matchalolz]

Let the integer be 10x + y, where x is the first digit and y is the second digit.

So your first expression is incorrect. It should be 8(x+y) = 10x + y.

Second expression should be 10x+y-45 = 10y+x.

thanks so much, i didn't realise that the first sentence was important oh wise one