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Question #8: Given the quadratic equation below, state how many x-intercepts it has.

[tex]\[ 2x^2 + 11x + 5 = 0 \][/tex]

A. 1
B. 2
C. 3
D. 0



Answer :

To determine the number of x-intercepts the quadratic equation [tex]\(2x^2 + 11x + 5 = 0\)[/tex] has, we need to calculate its discriminant. The discriminant of a quadratic equation in the form [tex]\(ax^2 + bx + c = 0\)[/tex] is found using the formula:

[tex]\[ \Delta = b^2 - 4ac \][/tex]

Here, the coefficients are:
- [tex]\(a = 2\)[/tex]
- [tex]\(b = 11\)[/tex]
- [tex]\(c = 5\)[/tex]

First, substitute the values of [tex]\(a\)[/tex], [tex]\(b\)[/tex], and [tex]\(c\)[/tex] into the formula for the discriminant:

[tex]\[ \Delta = 11^2 - 4 \cdot 2 \cdot 5 \][/tex]

Calculate [tex]\(11^2\)[/tex]:

[tex]\[ 11^2 = 121 \][/tex]

Next, calculate [tex]\(4 \cdot 2 \cdot 5\)[/tex]:

[tex]\[ 4 \cdot 2 = 8 \][/tex]

[tex]\[ 8 \cdot 5 = 40 \][/tex]

Subtract [tex]\(40\)[/tex] from [tex]\(121\)[/tex]:

[tex]\[ \Delta = 121 - 40 = 81 \][/tex]

Now, analyze the discriminant:
- If [tex]\(\Delta > 0\)[/tex], the quadratic equation has two distinct real x-intercepts.
- If [tex]\(\Delta = 0\)[/tex], the quadratic equation has exactly one real x-intercept.
- If [tex]\(\Delta < 0\)[/tex], the quadratic equation has no real x-intercepts.

In this case, the discriminant is [tex]\(\Delta = 81\)[/tex].

Since [tex]\(81 > 0\)[/tex], the quadratic equation [tex]\(2x^2 + 11x + 5 = 0\)[/tex] has two distinct real x-intercepts.

Therefore, the number of x-intercepts is:

[tex]\[ \boxed{2} \][/tex]