Answer: Option (B) would the best first step, take the square root of each side
Step-by-step explanation: When finding the solution to an algebraic expression, one of the most important rules that must never be forgotten is;
"whatever you do to the left side of the equation, you must equally do to the right side of the equation."
That in fact is why it is called an "equation," because all the expressions on either side of the equality sign ( = ) must have the same value.
The left hand side in this question is squared, or raised to the power of two. We can just find the square root and that becomes the number multiplied by itself. In other words, the square root of (x - 5)² is simply x - 5. Similarly we shall find the square root of 100 which we know equals 10.
Whenever an algebraic expression is squared (raised to the power of 2), adding the square root sign simplifies it. Hence, doing that for both sides of this equation is the best first step so far, as it would leave no remainder, or fraction.
The equation now can be solved as follows;
(x - 5)² = 100
Add the square root sign to both sides of the equation
√(x - 5)² = √100
x - 5 = 10
Add 5 to both sides of the equation
x = 15
