Question

A line has a gradient of 3 and passes through the point (-3,3). its y intercept is a)0 b)3 c)6 d)9 or e) 12

Answer 1

Recall the point-slope form:
y - y1 = m(x - x1)
where
(x1, y1) = a point on the line
m = slope or the gradient
In the problem, we have a gradient or slope = 3, and point (-3,3) on the line.
Substituting,
y - 3 = 3(x - (-3))
y - 3 = 3(x + 3)
y = 3x + 9 + 3
y = 3x + 12
Note that this form is the slope-intercept form (y = mx + b).
In the equation we got, the slope (m) is 3, and the y-intercept (b) is 12.

Hope this helps~ :)

Answer 2

find the gradient which passes through (-1,5) and (3,-30