IN THE REGENTS:

Algebraically determine the values of [tex]x[/tex] that satisfy the system of equations shown below:
[tex]\[
\begin{array}{l}
y = x^2 + 8x - 5 \\
y = 8x - 4
\end{array}
\][/tex]



Answer :

Sure! Let's determine the values of [tex]\( x \)[/tex] that satisfy the given system of equations:

[tex]\[ \begin{cases} y = x^2 + 8x - 5 \\ y = 8x - 4 \end{cases} \][/tex]

### Step 1: Set the equations equal to each other

Since both expressions equal [tex]\( y \)[/tex], we can set them equal to each other:

[tex]\[ x^2 + 8x - 5 = 8x - 4 \][/tex]

### Step 2: Simplify the equation

Subtract [tex]\( 8x \)[/tex] from both sides of the equation to eliminate [tex]\( 8x \)[/tex]:

[tex]\[ x^2 + 8x - 8x - 5 = 8x - 8x - 4 \][/tex]

This simplifies to:

[tex]\[ x^2 - 5 = -4 \][/tex]

Next, add 4 to both sides to isolate the [tex]\( x^2 \)[/tex] term:

[tex]\[ x^2 - 5 + 4 = -4 + 4 \][/tex]

This simplifies further to:

[tex]\[ x^2 - 1 = 0 \][/tex]

### Step 3: Solve the quadratic equation

Add 1 to both sides:

[tex]\[ x^2 = 1 \][/tex]

Now, take the square root of both sides:

[tex]\[ x = \pm 1 \][/tex]

So, the solutions for [tex]\( x \)[/tex] are [tex]\( x = 1 \)[/tex] and [tex]\( x = -1 \)[/tex].

### Step 4: Determine corresponding [tex]\( y \)[/tex] values

We need to find the corresponding [tex]\( y \)[/tex] values for [tex]\( x = 1 \)[/tex] and [tex]\( x = -1 \)[/tex] using one of the original equations, e.g., [tex]\( y = 8x - 4 \)[/tex].

- For [tex]\( x = 1 \)[/tex]:

[tex]\[ y = 8(1) - 4 = 8 - 4 = 4 \][/tex]

Thus, one solution is [tex]\( (1, 4) \)[/tex].

- For [tex]\( x = -1 \)[/tex]:

[tex]\[ y = 8(-1) - 4 = -8 - 4 = -12 \][/tex]

Thus, another solution is [tex]\( (-1, -12) \)[/tex].

### Conclusion

The values of [tex]\( x \)[/tex] that satisfy the system of equations are [tex]\( x = 1 \)[/tex] and [tex]\( x = -1 \)[/tex], with respective [tex]\( y \)[/tex] values of 4 and -12. Therefore, the solutions to the system of equations are:

[tex]\[ (-1, -12) \text{ and } (1, 4) \][/tex]