Question

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

x^2+4x=−3

x² + 2x + 1 = 0

4x^2−5=20

2x^2+3x=−3

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=(25)/(4)\\\\\\\Rightarrow x=\pm(5)/(2).`

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