Question

If x2=100 then x2-x=?

Answer 1

For this case we have the following expression:

`x^2=100`
From here we clear x, obtaining two possible results:

`x = +/- √(100)`

`x1=+√(100)=10`

`x2=-√(100)=-10`
Therefore we must evaluate the second expression for both values of x:

For x = 10:

`x^2-x=(10)^2-10 x^2-x= 100-10 x^2-x=90`

For x = -10

`x^2-x=(-10)^2-(-10) x^2-x= 100+10 x^2-x=110`

Answer 2

x² = 100
x² -x = ?
As x² = 100 = 10², it means x =10
So, x² - x = 100 - x = 90
90 is the answer.