How do you graph $ y = - 2x + 7 $ by plotting points?
Answer
627k+ views
Hint: In this question, we have to plot a linear equation in terms of two variables on the graph paper by plotting points. For graphing an equation by plotting points, we have to find the coordinates of at least two points lying on the line. As the equation is linear in terms of two unknown variables, that is, x and y so by putting random values of one variable we can find the value of the other value from the given equation. Using this approach, we find out the coordinates of two points lying on the line and get the graph of the line by joining these points.
Complete step-by-step answer:
The equation of the line is \[y = - 2x + 7\]
When $ x = 0 $
$
y = - 2(0) + 7 \\
\Rightarrow y = 7 \;
$
The line cuts the y-axis at the point $ (0,7) $
When $ y = 0 $
\[
0 = - 2x + 7 \\
\Rightarrow 2x = 7 \\
\Rightarrow x = \dfrac{7}{2} \;
\]
The line cuts the x-axis at the point $ (\dfrac{7}{2},0) $
Joining these two points and extending the obtained line away in the opposite directions, we can trace the line of the equation \[y = - 2x + 7\] .
Note: We use a graph to study the relation between two variable quantities, a graph contains two axes that are perpendicular to each other namely the x-axis and the y-axis. Instead of putting random values of the unknown quantity, we first put the value of x as zero and get the value of y, and then we put the value y as zero and get the value of x because the obtained points are more convenient and easier to plot on the graph.
Complete step-by-step answer:
The equation of the line is \[y = - 2x + 7\]
When $ x = 0 $
$
y = - 2(0) + 7 \\
\Rightarrow y = 7 \;
$
The line cuts the y-axis at the point $ (0,7) $
When $ y = 0 $
\[
0 = - 2x + 7 \\
\Rightarrow 2x = 7 \\
\Rightarrow x = \dfrac{7}{2} \;
\]
The line cuts the x-axis at the point $ (\dfrac{7}{2},0) $
Joining these two points and extending the obtained line away in the opposite directions, we can trace the line of the equation \[y = - 2x + 7\] .
Note: We use a graph to study the relation between two variable quantities, a graph contains two axes that are perpendicular to each other namely the x-axis and the y-axis. Instead of putting random values of the unknown quantity, we first put the value of x as zero and get the value of y, and then we put the value y as zero and get the value of x because the obtained points are more convenient and easier to plot on the graph.
Recently Updated Pages
What are the two major island groups in India class 9 social science CBSE

What is Jhum cultivation class 9 biology CBSE

Write an Article on Save Earth Save Life

Silk is obtained from of the silk moth APupa BLarva class 9 chemistry CBSE

Write chemical formulas of the following compounds class 9 chemistry CBSE

The Indo Gangetic Plains of India are fertile due to class 9 social science CBSE

Trending doubts
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE

Who was referred to as Amitraghata by the Greeks AChandragupta class 9 social science CBSE

Difference Between Plant Cell and Animal Cell

What is the full form of pH?

On an outline map of India show its neighbouring c class 9 social science CBSE

What is pollution? How many types of pollution? Define it


