Bookwork code: [tex]$4 F$[/tex]

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The straight line that passes through the points [tex]$(3, n)$[/tex] and [tex]$(6, 1)$[/tex] has a gradient of [tex]$\frac{4}{5}$[/tex].

What is the value of [tex]$n$[/tex]?

Give your answer as an integer or as a fraction in its simplest form.



Answer :

To find the value of [tex]\( n \)[/tex] where the line passes through the points [tex]\((3, n)\)[/tex] and [tex]\((6, 1)\)[/tex] and has a gradient (slope) of [tex]\(\frac{4}{5}\)[/tex], we use the formula for the gradient between two points:

[tex]\[ \text{Gradient} = \frac{y_2 - y_1}{x_2 - x_1} \][/tex]

Given:
- Points [tex]\((3, n)\)[/tex] and [tex]\((6, 1)\)[/tex]
- Gradient = [tex]\(\frac{4}{5}\)[/tex]

Substitute the given points into the gradient formula:
[tex]\[ \frac{1 - n}{6 - 3} = \frac{4}{5} \][/tex]

Simplify the denominator:
[tex]\[ \frac{1 - n}{3} = \frac{4}{5} \][/tex]

To clear the fraction, cross-multiply:
[tex]\[ 5 \cdot (1 - n) = 4 \cdot 3 \][/tex]

Simplify both sides:
[tex]\[ 5 - 5n = 12 \][/tex]

Isolate [tex]\( n \)[/tex] by first moving the constant term to the other side:
[tex]\[ -5n = 12 - 5 \][/tex]
[tex]\[ -5n = 7 \][/tex]

Divide both sides by [tex]\(-5\)[/tex]:
[tex]\[ n = \frac{7}{-5} \][/tex]
[tex]\[ n = -\frac{7}{5} \][/tex]

Thus, the value of [tex]\( n \)[/tex] is [tex]\(-\frac{7}{5}\)[/tex] which can also be written as [tex]\(-1.4\)[/tex]. However, since the problem specifies to give the answer as either an integer or a fraction in its simplest form, we keep it as:

[tex]\[ n = -\frac{7}{5} \][/tex]