Answer :
The system of equations is given by:
[tex]\[ \begin{array}{l} y = x^2 - 2x - 19 \\ y + 4x = 5 \end{array} \][/tex]
Step-by-step solution:
1. Substitute the second equation into the first:
Start by solving the second equation for [tex]\( y \)[/tex]:
[tex]\[ y = 5 - 4x \][/tex]
2. Substitute [tex]\( y \)[/tex] in the first equation:
Replace [tex]\( y \)[/tex] in the first equation:
[tex]\[ 5 - 4x = x^2 - 2x - 19 \][/tex]
3. Rearrange the equation:
Bring all terms to one side to form a quadratic equation:
[tex]\[ x^2 - 2x - 19 - 4x + 5 = 0 \][/tex]
Simplify the equation:
[tex]\[ x^2 - 6x - 14 = 0 \][/tex]
4. Solve the quadratic equation:
To solve for [tex]\( x \)[/tex], use the quadratic formula [tex]\( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \)[/tex], here [tex]\( a = 1 \)[/tex], [tex]\( b = -6 \)[/tex], and [tex]\( c = -14 \)[/tex]:
[tex]\[ x = \frac{-(-6) \pm \sqrt{(-6)^2 - 4 \cdot 1 \cdot (-14)}}{2 \cdot 1} \][/tex]
[tex]\[ x = \frac{6 \pm \sqrt{36 + 56}}{2} \][/tex]
[tex]\[ x = \frac{6 \pm \sqrt{92}}{2} \][/tex]
[tex]\[ x = \frac{6 \pm 2\sqrt{23}}{2} \][/tex]
[tex]\[ x = 3 \pm \sqrt{23} \][/tex]
Therefore, the [tex]\( x \)[/tex]-values are:
[tex]\[ x = -6 \quad \text{or} \quad x = 4 \][/tex]
5. Find the corresponding [tex]\( y \)[/tex]-values:
Substitute [tex]\( x = -6 \)[/tex] into [tex]\( y = 5 - 4x \)[/tex]:
[tex]\[ y = 5 - 4(-6) \][/tex]
[tex]\[ y = 5 + 24 \][/tex]
[tex]\[ y = 29 \][/tex]
Substitute [tex]\( x = 4 \)[/tex] into [tex]\( y = 5 - 4x \)[/tex]:
[tex]\[ y = 5 - 4(4) \][/tex]
[tex]\[ y = 5 - 16 \][/tex]
[tex]\[ y = -11 \][/tex]
Hence, the solution set is [tex]\((-6, 29)\)[/tex] and [tex]\((4, -11)\)[/tex].
So, the correct answer in the box is:
[tex]\[ (4, -11) \][/tex]
[tex]\[ \begin{array}{l} y = x^2 - 2x - 19 \\ y + 4x = 5 \end{array} \][/tex]
Step-by-step solution:
1. Substitute the second equation into the first:
Start by solving the second equation for [tex]\( y \)[/tex]:
[tex]\[ y = 5 - 4x \][/tex]
2. Substitute [tex]\( y \)[/tex] in the first equation:
Replace [tex]\( y \)[/tex] in the first equation:
[tex]\[ 5 - 4x = x^2 - 2x - 19 \][/tex]
3. Rearrange the equation:
Bring all terms to one side to form a quadratic equation:
[tex]\[ x^2 - 2x - 19 - 4x + 5 = 0 \][/tex]
Simplify the equation:
[tex]\[ x^2 - 6x - 14 = 0 \][/tex]
4. Solve the quadratic equation:
To solve for [tex]\( x \)[/tex], use the quadratic formula [tex]\( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \)[/tex], here [tex]\( a = 1 \)[/tex], [tex]\( b = -6 \)[/tex], and [tex]\( c = -14 \)[/tex]:
[tex]\[ x = \frac{-(-6) \pm \sqrt{(-6)^2 - 4 \cdot 1 \cdot (-14)}}{2 \cdot 1} \][/tex]
[tex]\[ x = \frac{6 \pm \sqrt{36 + 56}}{2} \][/tex]
[tex]\[ x = \frac{6 \pm \sqrt{92}}{2} \][/tex]
[tex]\[ x = \frac{6 \pm 2\sqrt{23}}{2} \][/tex]
[tex]\[ x = 3 \pm \sqrt{23} \][/tex]
Therefore, the [tex]\( x \)[/tex]-values are:
[tex]\[ x = -6 \quad \text{or} \quad x = 4 \][/tex]
5. Find the corresponding [tex]\( y \)[/tex]-values:
Substitute [tex]\( x = -6 \)[/tex] into [tex]\( y = 5 - 4x \)[/tex]:
[tex]\[ y = 5 - 4(-6) \][/tex]
[tex]\[ y = 5 + 24 \][/tex]
[tex]\[ y = 29 \][/tex]
Substitute [tex]\( x = 4 \)[/tex] into [tex]\( y = 5 - 4x \)[/tex]:
[tex]\[ y = 5 - 4(4) \][/tex]
[tex]\[ y = 5 - 16 \][/tex]
[tex]\[ y = -11 \][/tex]
Hence, the solution set is [tex]\((-6, 29)\)[/tex] and [tex]\((4, -11)\)[/tex].
So, the correct answer in the box is:
[tex]\[ (4, -11) \][/tex]