Question

A natural number is greater than three times its square root by 4. Find the number.​

Answer 1

let no.=x

thus,

(x½)3+4=x

3√x=x-4

squaring both sides,

9x=x²+16-8x

x²+16-17x=0

thus,

x²-16x-x+16=0

x(x-16)-1(x-16)

Answer 2

Answer:

16

Step-by-step explanation:

let that natural no. be x

3√x + 4 = x

let √x = t => x = t^2

3t + 4 = t^2 => t^2 - 3t - 4 = 0

t^2 - 4t + t - 4 = 0

t(t - 4) + 1( t - 4) = 0 => t = 4 , - 1

neglect -1 becoz a natural number is always a + ve number.

so t = 4 => √x = 4 => x = (4)^2 = 16

required number x = 16