Q. find the x-intercept of the line 5x + 18y = 4.
Answer
see the next answer here to check Set y=0: \(5x+18\cdot 0=4\) so \(5x=4\) and \(x=\tfrac{4}{5}\). The x-intercept is \(\left(\tfrac{4}{5},0\right)\).
Detailed Explanation
Problem
Find the x-intercept of the line given by the equation \(5x + 18y = 4\).
Explanation and step-by-step solution
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Recall the definition of an x-intercept.
The x-intercept is the point where the graph of the line crosses the x-axis. At any point on the x-axis the y-coordinate is 0. Therefore to find the x-intercept we set \(y = 0\) in the equation of the line.
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Substitute \(y = 0\) into the equation.
Starting from the given equation, substitute \(y = 0\):
\[5x + 18\cdot 0 = 4\]
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Simplify the equation after substitution.
Evaluate the product \(18\cdot 0\):
\[5x + 0 = 4\]
Which simplifies to
\[5x = 4\]
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Solve for \(x\).
Divide both sides of the equation by 5 to isolate \(x\):
\[x = \frac{4}{5}\]
Optionally, express as a decimal:
\[x = 0.8\]
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Write the x-intercept as a coordinate point.
The x-intercept is the point on the x-axis with this x-coordinate and y = 0, so the x-intercept is
\[\left(\frac{4}{5},\,0\right)\]
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Quick check (optional but instructive).
Substitute the point \(\left(\frac{4}{5},0\right)\) into the original equation to verify:
\[5\left(\frac{4}{5}\right) + 18(0) = 4 + 0 = 4\]
Since the left-hand side equals the right-hand side, the point is correct.
Final answer
The x-intercept is \(\left(\frac{4}{5},0\right)\) (which is \((0.8,0)\)).
Graph
FAQs
How do you find the x-intercept of \(5x+18y=4\)?
What is the y-intercept of \(5x+18y=4\)?
How do you convert \(5x+18y=4\) to slope-intercept form?
What is the slope of the line \(5x+18y=4\)?
How can I check my x-intercept calculation?
How do I write the equation in intercept form?
How would I graph this line quickly?
What if the coefficient of \(y\) were zero?
Use y = 0 to solve for x.
Math, Calculus, Geometry, etc.