PLEASE HELP AND ANSWER!!!!! Which of the following reveals the minimum value for the equation 2x2 + 12x − 14 = 0?

2(x + 6)2 = 26
2(x + 6)2 = 20
2(x + 3)2 = 32
2(x + 3)2 = 30

Respuesta :

Answer:

The correct option is 3.

Step-by-step explanation:

The given equation is

[tex]2x^2+12x-14=0[/tex]

It can be written as

[tex](2x^2+12x)-14=0[/tex]

Taking out the common factor form the parenthesis.

[tex]2(x^2+6x)-14=0[/tex]

If an expression is defined as [tex]x^2+bx[/tex] then we add [tex](\frac{b}{2})^2[/tex] to make it perfect square.

In the above equation b=6.

Add and subtract 3^2 in the parenthesis.

[tex]2(x^2+6x+3^2-3^2)-14=0[/tex]

[tex]2(x^2+6x+3^2)-2(3^2)-14=0[/tex]

[tex]2(x+3)^2-18-14=0[/tex]

[tex]2(x+3)^2-32=0[/tex]             .... (1)

Add 32 on both sides.

[tex]2(x+3)^2=32[/tex]

The vertex from of a parabola is

[tex]p(x)=a(x-h)^2+k[/tex]        .... (2)

If a>0, then k is minimum value at x=h.

From (1) and (2) in is clear that a=2, h=-3 and k=-32. It means the minimum value is -32 at x=-3.

The equation [tex]2(x+3)^2=32[/tex] reveals the minimum value for the given equation.

Therefore the correct option is 3.

Answer:

2(x + 3)^2 = 32

Step-by-step explanation:

The "COMPLETING THE SQUARE" lesson makes it clear that this is the correct answer.

(I just took the test)