Solve the following system of equations by graphing: x + 2y = 8 x - y = 2

Understand the Problem
The question asks to solve a system of two linear equations by graphing. This involves plotting each equation on a coordinate plane and finding the point where the two lines intersect, which represents the solution to the system.
Answer
$(4, 2)$
Answer for screen readers
$(4, 2)$
Steps to Solve
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Solve each equation for $y$ Isolate $y$ in each equation to express them in slope-intercept form ($y = mx + b$). For the first equation: $x + 2y = 8$ $2y = -x + 8$ $y = -\frac{1}{2}x + 4$ For the second equation: $x - y = 2$ $-y = -x + 2$ $y = x - 2$
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Find two points for each line Choose two $x$ values and calculate the corresponding $y$ values for each equation: For $y = -\frac{1}{2}x + 4$: If $x = 0$, $y = -\frac{1}{2}(0) + 4 = 4$. Point: $(0, 4)$ If $x = 2$, $y = -\frac{1}{2}(2) + 4 = -1 + 4 = 3$. Point: $(2, 3)$
For $y = x - 2$: If $x = 0$, $y = 0 - 2 = -2$. Point: $(0, -2)$ If $x = 2$, $y = 2 - 2 = 0$. Point: $(2, 0)$
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Plot the points and draw the lines Plot the points found in step 2 on a coordinate plane and draw a straight line through the points for each equation.
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Find the intersection point Identify the point where the two lines intersect on the graph. This point represents the solution to the system of equations. From the graph, the intersection point appears to be $(4, 2)$.
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Verify the solution Substitute the $x$ and $y$ values of the intersection point into both original equations to check if the solution is correct. For $x + 2y = 8$: $4 + 2(2) = 4 + 4 = 8$. The equation holds true. For $x - y = 2$: $4 - 2 = 2$. The equation holds true.
$(4, 2)$
More Information
The solution to a system of linear equations represents the point where the lines intersect, graphically. This point satisfies both equations simultaneously. If the lines are parallel, there is no solution; if they are the same line, there are infinitely many solutions.
Tips
- Incorrectly solving for $y$, leading to incorrect slope-intercept form.
- Plotting points inaccurately, resulting in an incorrect graph.
- Misreading the intersection point from the graph.
- Not verifying the solution by substituting the values back into the original equations.
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