Question

For which equation does it make the most sense to solve by using the square root property?

Answer 1

Just took the test, the answer is C.
:)

Answer 2

Answer: The answer is (c) $4x^2-5=20.$

Step-by-step explanation:  We are given four quadratic equations out ofehich we are to select the one which can be best solved by the square root property.

We can see that the equations $x^2+4x=-3,~x^2+2x+1=0,~\textup{and}~2x^2+3x=-3$ invove the single power of 'x', so hey can be solved by completing the square method.

But the equation $4x^2-5=20$ does not involve x, only x², so it makesthe most sense to solve this equation by square root method. The solution is as follows:

$4x^2-5=20\\\\\Rightarrow 4x^2=25\\\\\\\Rightarrow x^2=\dfrac{25}{4}\\\\\\\Rightarrow x=\pm\dfrac{5}{2}.$

Thus, the correct option is (c) $4x^2-5=20.$