How do you work this maths sum out?

[MoSalahsBeard]

Write an equation for the following for the following in the form y=mx+c:

gradient of 2, y- intercept of 3?

Y=2x+3

Y= gradient X plus intercept

I would say .....

Y = tomatoes on the rood
X+ dinosaurs

Therefore intercept 3 goes to mars

y = 2x + 3

Gradient is the slope. It is the m value. It tells you how fast y changes for every unit change in x.

y intercept is the c value. It asks, if x=zero, what is y.

y=2x+3

m is the gradient, c is the y-intercept.
Just insert the numbers instead of the letters, nothing to really work out.

y = 2x + 3

If you're wanting to understand it further.

The y intercept is the point where x = 0.
So y = m* 0 +c
anything (assuming m isn't either + or - infinity) times 0 equals 0, so when x = 0, then y = c.

Gradient is slightly harder.
Gradient = change in y / change in x

So to make is simply look at two points, the first is nice and easy x = 0, y = c, so point (0, c)
Take the second point when x = 1. x=1, y=m+c, so second point is (1, m+c)

Change in x = 1-0=1
Change in y = (m+c) -c = m
Therefore gradient = m/1 = m

This equation describes a straight line where to find the Y value you double the X value and then add 3. This gives a gradient of positive 2, crossing the Y axis where Y = 3.

As a PP said, in this particular question there is nothing to actually work out; you just substitute the two numbers you've been given into the equation.

NB Any other line with the same gradient will be parallel.