IDNStudy.com, kung saan ang mga eksperto ay sumasagot sa iyong mga tanong. Magtanong ng anumang bagay at makatanggap ng kumpleto at eksaktong sagot mula sa aming komunidad ng mga propesyonal.

2.) Which of the following expressions represents a quadratic equation?
I. (x+5) (x+5) =3
II. x2 = -2x + 5
III. 2x - 1 = 3x + 7
a. I only
b. III only
c. ll only
d. I and II​


Sagot :

QUADRATIC EQUATION

==============================

Question:

Which of the following expressions represents a quadratic equation?

I. (x+5) (x+5) = 3

II. x2 = -2x + 5

III. 2x - 1 = 3x + 7

==============================

Answer:

D. I and II

==============================

Why?

  • Choice I

[tex] \sf {(x + 5)}^{2} = 3 \\ \sf {x}^{2} + 10x + 25 = 3 \\ \sf {x}^{2} + 10x + 25 - 3 = 0 \\ \boxed{\sf {x}^{2} + 10x + 22 = 0}[/tex]

This is Quadratic Equation, with the root of...

[tex] \sf x = - 5 ± \sqrt{3} [/tex]

.

.

  • Choice II

[tex] \sf{x}^{2} = - 2x + 5 \\ \boxed{ \sf{x}^{2} + 2x - 5 = 0}[/tex]

This is Quadratic Equation, with the root of...

[tex] \sf x = - 1 ± \sqrt{6} [/tex]

.

.

  • Choice III

[tex] \sf2x - 1 = 3x + 7 \\ \sf2x - 3x = 7 + 1 \\ \sf - x = 8 \\ \boxed{\sf x = - 8}[/tex]

This is NOT Quadratic Equation, the value of x is -8

.

#CarryOnLearning

(ノ^_^)ノ