Question

How do you solve `x^2=90`?

Answer 1

x=+-3`sqrt`10

Explanation:

Taking the square root of any number gives you two answers, one positive and one negative e.g. -2 x -2 =4
Square root of 90 = square root of 9 x 10
You can root the 3 to give 3`sqrt`10

Answer 2

`x=3sqrt(10) larr" exact value"`

Explanation:

Using the 'Principle square root'. That is, the positive one.

Square root both sides

`sqrt(x^2)=sqrt(90)`

`x=sqrt(3^2xx10)`

`x=3sqrt(10) larr" exact value"`

Not that the decimal equivalent would be rounded and thus not as precise.