Question

How do you find the x and y intercept of `x – 9y = – 45`?

Answer 1

Here it is

Explanation:

Hopefully, you have already learnt the equation of a line which states that

`color(red)"y = mx + c"`

where m is the gradient (m = y/x) and c is the y-intercept. (and x and y the coordinates.)

Now arranging your equation into above mentioned format;

`x– 9y= –45`

`-9y = -x -45`

`y = (-x)/-9 +( -45)/-9`

`y =1/9*x+5`

Now you from this equation you can see that #color(Magenta)"1/9 is the gradient m "#and `color(blue)"5 is c which is the y intercept."`

SO OUR Y-INTERCEPT IS FOUND WHICH IS 5.

Now for finding x-intercept then y coordinate must be equal to ZERO.

So we put the equation equal to ZERO, like this:

`0 = 1/9*x + 5`

`-5 = 1/9*x`

`x = -45`

SO at -45 the line intersects the x-axis.

SO OUR X-INTERCEPT EQUALS TO -45.