Question 1146954
let x = the value of the tens digit.
let y = the value of the ones digit.
the number is 10x + y.
example: in the number 57, 5 is the value of the tens digit and 7 is the value of the ones digit and the number is 10 * 5 + 7 = 57.
this is because each tens digit is worth 10 units while each units digit is worth 1 unit.
your equations are:
x + 5y = 43
5x + y = 47
multiply both sides of the first equation by 5 and leave the second equation as is to get:
5x + 25y = 215
5x + y = 47
subtract the second equation from the first to get:
24y = 168
solve for y to get:
y = 7
replace y with 7 in the second equation of 5x + y = 47 to get:
5x + 7 = 47
subtract 7 from both sides to get:
5x = 40
solve for x to get:
x = 8
replace x with 8 and y with 7 in both original equqations to get:
x + 5y = 43 becomes 8 + 35 = 43 which becomes 43 = 43 which is true.
5x + y = 47 becomes 40 + 7 = 47 which becomes 47 = 47 which is true.
both original equation are true when x = 8 and y = 7.
your number is 10x + y which is equal to 87.
that's your solution.