Question

D. 00
(i) The sum of a natural number and its square
is 42. Find the number.​

Answer 1

Answer:

6

To solve : Let the number be $n$.

*Then its square is equal to $n^2$.

*Their sum means $n^2+n$.

By using the quadratic equation $n^2+n=42$,

we are going to find the solution.

$n^2+n-42=0$ → In The $ax^2+bx+c=0$ Form

By the a.c method,

$(n-6)(n+7)=0$.

∴  $n=6,-7$ by factorization method.

Since $n$ is a natural number, answer is 6.