This table gives a few [tex]$(x, y)$[/tex] pairs of a line in the coordinate plane.

[tex]\[
\begin{tabular}{cc}
$x$ & $y$ \\
\hline
-28 & -54 \\
-21 & -40 \\
-14 & -26 \\
\end{tabular}
\][/tex]

What is the [tex]$y$[/tex]-intercept of the line?
[tex]$\square$[/tex]



Answer :

To determine the [tex]\( y \)[/tex]-intercept of the line, we need to find the equation of the line in the form [tex]\( y = mx + b \)[/tex], where [tex]\( m \)[/tex] represents the slope and [tex]\( b \)[/tex] represents the [tex]\( y \)[/tex]-intercept.

First, let's calculate the slope [tex]\( m \)[/tex]. The slope [tex]\( m \)[/tex] of the line that passes through two points [tex]\((x_1, y_1)\)[/tex] and [tex]\((x_2, y_2)\)[/tex] is given by:
[tex]\[ m = \frac{y_2 - y_1}{x_2 - x_1} \][/tex]

Let's use the points [tex]\((-28, -54)\)[/tex] and [tex]\((-21, -40)\)[/tex] from the table to find the slope.

[tex]\[ m = \frac{-40 - (-54)}{-21 - (-28)} = \frac{-40 + 54}{-21 + 28} = \frac{14}{7} = 2 \][/tex]

Now we know the slope [tex]\( m \)[/tex] is 2.

Next, we need to find the [tex]\( y \)[/tex]-intercept [tex]\( b \)[/tex]. We can use any of the given points and plug them into the line equation [tex]\( y = mx + b \)[/tex] to solve for [tex]\( b \)[/tex]. Let's use the point [tex]\((-28, -54)\)[/tex].

Starting with the slope-intercept form:
[tex]\[ y = mx + b \][/tex]

Substitute [tex]\( y = -54 \)[/tex], [tex]\( m = 2 \)[/tex], and [tex]\( x = -28 \)[/tex]:
[tex]\[ -54 = 2(-28) + b \][/tex]

Simplify and solve for [tex]\( b \)[/tex]:
[tex]\[ -54 = -56 + b \][/tex]
[tex]\[ b = -54 + 56 \][/tex]
[tex]\[ b = 2 \][/tex]

So, the [tex]\( y \)[/tex]-intercept of the line is [tex]\( 2 \)[/tex].

Thus, the [tex]\( y \)[/tex]-intercept is
[tex]\[ \boxed{2} \][/tex]