Find the unique two-digit number such that the square of the sum of digits equals the number obtained
by reversing its digits. [50 points]

Respuesta :

MsMyah

Answer:

10a+b = a two digit number

:

write what it says:

:

"A 2 digit number which has the square of the sum of its digits

equal to the number obtained by reversing it's digit?"

(a+b)^2 = 10b + a

We have two unknown with only one equation

Assume a = 1, find b

(1+b)^2 = 10b + 1

1 + 2b + b^2 = 10b + 1

:

b^2 + 2b - 10b = 1 - 1

b^2 - 8b = 0

divide both sides by b

b - 8= 0

b = 8

then the number is 18; (9^2 = 81)

:

I don't think there is any other number, except perhaps 10

(1+0)^2 = 0 + 1