Questions: Find all solutions of the system of equations algebraically. Write your solutions as coordinate points.
y=-3 x^2+26 x-46
x+y=8
Transcript text: Find all solutions of the system of equations algebraically. Write your solutions as coordinate points.
\[
\begin{array}{c}
y=-3 x^{2}+26 x-46 \\
x+y=8
\end{array}
\]
Solution
Solution Steps
To solve the system of equations algebraically, we can use substitution. First, express \( y \) from the second equation in terms of \( x \). Then, substitute this expression into the first equation to form a quadratic equation in terms of \( x \). Solve the quadratic equation to find the values of \( x \). Finally, substitute these \( x \) values back into the expression for \( y \) to find the corresponding \( y \) values. The solutions will be the coordinate points \((x, y)\).
Step 1: Set Up the System of Equations
We start with the system of equations:
\[
\begin{align_}
y &= -3x^2 + 26x - 46 \quad (1) \\
x + y &= 8 \quad (2)
\end{align_}
\]
Step 2: Substitute and Solve
From equation (2), we can express \( y \) in terms of \( x \):
\[
y = 8 - x
\]
Substituting this into equation (1):
\[
8 - x = -3x^2 + 26x - 46
\]
Rearranging gives us:
\[
3x^2 - 26x + x + 46 + 8 = 0 \implies 3x^2 - 25x + 54 = 0
\]
Step 3: Find the Roots
Solving the quadratic equation \( 3x^2 - 25x + 54 = 0 \) yields the solutions:
\[
x = 3 \quad \text{and} \quad x = 6
\]
Step 4: Calculate Corresponding \( y \) Values
Substituting \( x = 3 \) into \( y = 8 - x \):
\[
y = 8 - 3 = 5
\]
Substituting \( x = 6 \):
\[
y = 8 - 6 = 2
\]
Final Answer
The solutions to the system of equations are the coordinate points:
\[
\boxed{(3, 5)} \quad \text{and} \quad \boxed{(6, 2)}
\]