Question

How to solve ,step by step

Answer 1

Answer:

gradient = slope = $\frac{y_{2} -y_{1} }{x_{2} -x_{1} }$ = $\frac{rise}{run}$

Slope intercept Form equation : y = mx + b

m = slope or gradient

b = y - intercept ( where the line crosses the y = axis)

x and y = are place holders for a coordinate pair that makes the equation true

c) y = -6x + 8

The -6 is the m. It's the slope or gradient.

the + 8  is the b. It's the y- intercept.

d) y = 4

This is a horizontal line. It intercepts the y-axis at 4.

That means the 4 is the y-intercept.

There is no x. That means the slope is 0. The line rises 0 as it runs left to right.

e) y -4x= 0  

equation needs to be is standard form y = mx + b.

add 4x to both sides in order to isolate the y variable.

y = 4x + 0.

The slope or gradient is 4. The y - intercept is 0. The line crosses through the origin.

f) y -x = -8

Add x to both sides.

y = x - 8

There is one x.  That means the gradient is 1. The y-intercept is the -8

g) y + 3x = 7

Subtract 3x from both sides.

y = -3x + 7

-3 = gradient. 7 = y-intercept.

h) y + $\frac{1}{2}$x = -4

Subtract $\frac{1}{2}$x from each side.

y = -$\frac{1}{2}$x - 4

One last thing. If you are presented with an equation without a y, the gradient is  'undefined'.

example : x = 4

This a vertical line passing through 4 on the x-axis. There is no 'b' because its not crossing the y-axis.

Why is it 'undefined' ?

As the line rises it, it does not 'run' left or right. $\frac{rise}{0}$ . Zero can never, ever be in the denominator. Denominators can't be zero. That is why we say it's 'undefined'.

Hope this helps.