Simultaneous Equations 7
1. Problem: Solve the simultaneous linear equations $2x + y = 8$ and $x + y = 5$ by graphing.
2. Step 1: Identify the system type. These are simultaneous linear equations because there are two linear equations with two variables.
3. Step 2: Express each equation in slope-intercept form $y = mx + b$ for graphing.
For $2x + y = 8$, subtract $2x$ from both sides:
$$y = 8 - 2x$$
For $x + y = 5$, subtract $x$ from both sides:
$$y = 5 - x$$
4. Step 3: Graph both lines on the coordinate plane. The lines are straight because these are first degree equations.
5. Step 4: Find the point of intersection of the lines which satisfy both equations.
Set the right hand sides equal:
$$8 - 2x = 5 - x$$
Simplify:
$$8 - 2x = 5 - x$$
$$8 - 5 = -x + 2x$$
$$3 = x$$
6. Step 5: Substitute $x=3$ into one equation to find $y$.
Using $y = 5 - x$:
$$y = 5 - 3 = 2$$
7. Final Answer: The solution to the system is
$$x = 3, y = 2$$
This means the lines intersect at the point $(3,2)$, solving the simultaneous equations.