Question

If an integer is added to its square, the sum is 90. find the integer

Answer 1

Let the required no. be x.

therefore, $x^{2}$ + x = 90
            or, $x^{2}$ + x - 90 = 0
            or, (x - 9)(x +10) = 0
Therefore, x = 9 or -10

Answer 2

Answer:

Step-by-step explanation:

let integer be x

it's square =x^2

if x is added to its square then, the result is x^2+x.

according to problem

x^2+x=90

I. e,

x^2+x-90=0

x^2+10x-9x-90=0

x(x+10)-9(x+10)=0

x-9=0. or x+10=0

then, x=9 or -10

OK