Step-by-step explanation:
For Sienna to be able to take the square root of both sides while solving a quadratic equation, she must have an expression with square on at least, the side that contains the variable she is trying to determine. Equation of the form:
(x + a) ² = b
'a' and 'b' could be any number, -1, 0, 1/3, -5/6, anything really.
So, she can take square roots of both sides then, like this
√(x + a)² = √b
x + a = ±√b
x = -a ± √b
Square roots always cancel out squares, and the '±' is because a square is satisfies by both + and -, 3² = 9, and (-3)² = 9.
It is the nature of the problem being solved that determines if we take just one or both of these answers.