Intercept

Another important property of a line (or any curve on a coordinate plane) are its x- and y-intercepts: the points where the line intersects coordinate axes. Watch this lecture series and complete the interactive exercises.

Intercepts from an equation - Questions

Answers

1.

The y-intercept is the point where the graph intersects the y-axis. Since the y-axis is also the line x = 0, the x-value of this point will always be 0.

The x-intercept is the point where the graph intersects the x-axis. Since the x-axis is also the line y = 0, the y-value of this point will always be 0.

To find the y-intercept, let's substitute x = 0 into the equation and solve for y:

\begin{aligned}
4 \cdot 0-3 y &=17 \\
-3 y &=17 \\
y &=-\frac{17}{3}
\end{aligned}

So the y-intercept is \left(0,-\frac{17}{3}\right).

To find the x intercept, let's substitute y = 0 into the equation and solve for x:

\begin{array}{r}
4 x-3 \cdot 0=17 \\
4 x=17 \\
x=\frac{17}{4}
\end{array}

So the x-intercept is \left(\frac{17}{4}, 0\right).

In conclusion,

  • The y-intercept is \left(0,-\frac{17}{3}\right).
  • The x-intercept is \left(\frac{17}{4}, 0\right).


2.

The y-intercept is the point where the graph intersects the y-axis. Since the y-axis is also the line x = 0, the x-value of this point will always be 0.

The x-intercept is the point where the graph intersects the x-axis. Since the x-axis is also the line y = 0, the y-value of this point will always be 0.

To find the y-intercept, let's substitute x = 0 into the equation and solve for y:

\begin{aligned}
y-3 &=5(0-2) \\
y-3 &=-10 \\
y &=-7
\end{aligned}

So the y-intercept is  (0, -7).

To find the x intercept, let's substitute y = 0 into the equation and solve for x:

\begin{aligned}
0-3 &=5(x-2) \\
-3 &=5 x-10 \\
7 &=5 x \\
1.4 &=x
\end{aligned}

So the x-intercept is  (1.4, 0).

In conclusion,

  • The y-intercept is  (0, -7).
  • The x-intercept is  (1.4, 0).


3.

The x-intercept is the point where the graph intersects the x-axis. Since the x-axis is also the line y = 0, the y-value of this point will always be 0.

The y-intercept is the point where the graph intersects the y-axis. Since the y-axis is also the line x = 0, the x-value of this point will always be 0.

To find the x intercept, let's substitute y = 0 into the equation and solve for x:

\begin{aligned}
0 &=11 x+6 \\
-6 &=11 x \\
-\frac{6}{11} &=x
\end{aligned}

So the x-intercept is \left(-\frac{6}{11}, 0\right).

To find the y-intercept, let's substitute x = 0 into the equation and solve for y:

\begin{aligned}
&y=11 \cdot 0+6 \\
&y=6
\end{aligned}

So the y-intercept is  (0, 6) . Generally, in linear equations of the form y=m x+b (which is called slope-intercept form), the y-intercept is ( 0, b) .

In conclusion,

  • The x-intercept is \left(-\frac{6}{11}, 0\right).
  • The y-intercept is  (0, 6) .


4.

The y-intercept is the point where the graph intersects the y-axis. Since the y-axis is also the line x = 0, the x-value of this point will always be 0.

The x-intercept is the point where the graph intersects the x-axis. Since the x-axis is also the line y = 0, the y-value of this point will always be 0.

To find the y-intercept, let's substitute x = 0 into the equation and solve for y:

\begin{aligned}
-7 \cdot 0-6 y &=-15 \\
-6 y &=-15 \\
y &=\frac{15}{6} \\
y &=\frac{5}{2}
\end{aligned}

So the y-intercept is \left(0, \frac{5}{2}\right).

To find the x intercept, let's substitute y = 0 into the equation and solve for x:

\begin{aligned}
-7 x-6 \cdot 0 &=-15 \\
-7 x &=-15 \\
x &=\frac{15}{7}
\end{aligned}

So the x-intercept is \left(\frac{15}{7}, 0\right).

In conclusion,

  • The y-intercept is \left(0, \frac{5}{2}\right).
  • The x-intercept is \left(\frac{15}{7}, 0\right).