Select the correct answer.

What is the solution set of [tex]$y=x^2+2x+7$[/tex] and [tex]$y=x+7$[/tex]?

A. [tex]\{(0,7),(-1,6)\}[/tex]

B. [tex]\{(0,7),(-7,0)\}[/tex]

C. [tex]\{(0,7),(1,8)\}[/tex]

D. [tex]\{(-2,0),(4,0)\}[/tex]



Answer :

To find the solution set of the equations [tex]\( y = x^2 + 2x + 7 \)[/tex] and [tex]\( y = x + 7 \)[/tex], we need to determine the points where these two equations intersect. This can be done by setting the equations equal to each other and solving for [tex]\( x \)[/tex].

Step 1: Set the equations equal to each other.
[tex]\[ x^2 + 2x + 7 = x + 7 \][/tex]

Step 2: Simplify the equation by moving all terms to one side.
[tex]\[ x^2 + 2x + 7 - (x + 7) = 0 \][/tex]

[tex]\[ x^2 + 2x - x + 7 - 7 = 0 \][/tex]

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

Step 3: Factor the equation.
[tex]\[ x(x + 1) = 0 \][/tex]

Step 4: Solve for [tex]\( x \)[/tex].
[tex]\[ x = 0 \quad \text{or} \quad x = -1 \][/tex]

Step 5: Substitute these values of [tex]\( x \)[/tex] back into either of the original equations to find the corresponding values of [tex]\( y \)[/tex].

For [tex]\( x = 0 \)[/tex]:
[tex]\[ y = 0 + 7 = 7 \][/tex]

For [tex]\( x = -1 \)[/tex]:
[tex]\[ y = -1 + 7 = 6 \][/tex]

Thus, the points of intersection are [tex]\((0, 7)\)[/tex] and [tex]\((-1, 6)\)[/tex].

So, the solution set is:
[tex]\[ \{(0, 7), (-1, 6)\} \][/tex]

Therefore, the correct answer is:
A. [tex]\(\{(0, 7), (-1, 6)\}\)[/tex]