Question

Help please !

Answer 1

Strong advise that you plot these points and draw a line through them.  Also, expressing functions in words is cumbersome; why not convert all those words into appropriate symbols?  

From the given data:

x y
−3 9
−1 3
0 0
3 −9

You can see that as x increases, y decreases.  If this is a straight line, then the slope of the line is negative.  If you'll plot these points and connect them with a line / curve (you decide which is correct), the shape of the graph should be obvious.  What is the slope of this graph?

Answer 2

Answer:

(1) Required function is  $y=-3x$ . (2) Slope of line is $-\frac{1}{5}$ .

Step-by-step explanation:

1)

The function passing through (-3,9), (-1,3), (0,0) and (3,-9).

From these points it is noticed that the value of function decrease by 6 if the value of x increases by 2 and y-intercept is (0,0).

$m=\frac{\text{change in y}}{\text{change in x}}=\frac{-6}{2}=-3$

Slope intercept of a line is

$y=mx+b$

Where, m is slope and b is y-intercept.

So, function is defined as

$y=-3x+0$

$y=-3x$

The required function is  $y=-3x$ .

2)

It is given that the line joining two points (10, 9) and (40, 3).

Slope of line is

$m=\frac{y_2-y_1}{x_2-x_1}$

$m=\frac{3-9}{40-10}=\frac{-6}{30}=-\frac{1}{5}$

Therefore slope of line is $-\frac{1}{5}$ .