This system has one solution.
[tex]\[ \left\{\begin{array}{l} y = 5x - 9 \\ y = x^2 - 3x + 7 \end{array}\right. \][/tex]

What is the [tex]\( y \)[/tex]-coordinate of the solution?

Enter your answer in the box.
[tex]\[ y = \square \][/tex]



Answer :

To determine the [tex]\( y \)[/tex]-coordinate of the intersection of the two equations [tex]\( y = 5x - 9 \)[/tex] and [tex]\( y = x^2 - 3x + 7 \)[/tex], we need to find a common [tex]\( x \)[/tex] value that satisfies both equations. Here is the step-by-step solution:

1. Set the equations equal to each other: Since [tex]\( y \)[/tex] is the same in both equations at the point of intersection, we equate the two expressions for [tex]\( y \)[/tex]:

[tex]\[ 5x - 9 = x^2 - 3x + 7 \][/tex]

2. Rearrange to form a quadratic equation: Move all terms to one side to set the equation to zero:

[tex]\[ x^2 - 3x + 7 - 5x + 9 = 0 \implies x^2 - 8x + 16 = 0 \][/tex]

3. Solve the quadratic equation: Factorize the equation [tex]\( x^2 - 8x + 16 = 0 \)[/tex]:

[tex]\[ (x - 4)(x - 4) = 0 \implies (x - 4)^2 = 0 \implies x = 4 \][/tex]

This quadratic equation has a double root [tex]\( x = 4 \)[/tex].

4. Find the corresponding [tex]\( y \)[/tex]-coordinate: Substitute [tex]\( x = 4 \)[/tex] back into either of the original equations to find [tex]\( y \)[/tex]. Using the first equation [tex]\( y = 5x - 9 \)[/tex]:

[tex]\[ y = 5(4) - 9 \implies y = 20 - 9 \implies y = 11 \][/tex]

Thus, the [tex]\( y \)[/tex]-coordinate of the solution is:

[tex]\[ y = 11.0 \][/tex]

Therefore, the [tex]\( y \)[/tex]-coordinate of the intersection of the two given equations is:

[tex]\[ y = 11 \][/tex]