Question

a natural number of two digits is 7 times the sum of the digits digits in the tens place is half the square of the digit in units place find the number​

Answer 1

Answer:

84

Step-by-step explanation:

let x & y be the 2 digits of the required number.

so the number is 10x+y

given that,

10x+y = 7(x+y)  

=> 10x+y = 7x+7y

=>  10x-7x = 7y -y

=> 3x = 6y

=> x = 2y -------------- (1)

also,

x = 1/2(y²)

substitute the x value from (1) in the above equation.

we get,

2y = 1/2(y²)

=> 4y = y²

=> y²/y = 4

=> y=4

substitute the value of y in (1)

=> x = 2(4) = 8

∴ the number is 10(8)+4 = 80+4 = 84