Question

Sum of a number and its square is 30. Which is the number​

Answer 1

Answer:

let's call our number x.

To write this question in equation form...

the sum (+)

of a number (x)

and it's square (x2)

is 30

x + x2 = 30

Let's set our equation equal to zero:

x + x2 = 30

x2 + x - 30 = 0

now we can use the quadratic formula to solve:

x = ([ ±√(1 - 4*1*-30)] / 2

x = -1/2 ±√(121)/2

x = -1/2 ±11/2

x = -0.5 ± 5.5

x = 5, -6

There are two solutions.

5+52 = 5 + 25 = 30

-6 + (-6)2 = -6 + 36 = 30