The equations above are all in the format [tex]y = mx + c[/tex], where [tex]m[/tex] = the gradient, or slope.
So, in the first question, [tex]y = 4x + 2[/tex], the gradient would be 4, because 4 is [tex]m[/tex] in this equation (the number before the [tex]x[/tex]).
The gradient of a line perpendicular to this line is equal to the negative reciprocal of the gradient of the line. A better way to explain it is if [tex]m[/tex] = the gradient of the line and [tex]m'[/tex] = the gradient of the perpendicular line then:
[tex]m' = - \frac{1}{m} [/tex]
So in the first question, the gradient of the perpendicular line is [tex]- \frac{1}{4} [/tex].
