Assume that the initial coordinates are (x,y) and that the dilated coordinates are (x',y').
The dilation is therefore:
(x,y) ............> (x',y')
Now, let's assume that the dilation factor is k.
Therefore:
x' = kx
y' = ky
Based on the above, all the student has to do is get the initial coordinates and the final ones and then substitute in any of the above two equations to get the value of k.
Example:
Assume an original point at (2,4) is dilated to coordinates (4,8). Find the dilation factor.
Assume the dilation coefficient is k.
(x,y) are (2,4) and (x',y') are (4,8)
Therefore:
x' = kx .........> 4 = k*2 ..........> k = 2
or:
y' = ky ..........> 8 = k*4 .........> k = 2
Based on the above, the dilation coefficient would be 2.
Hope this helps :)
Straight line:
y = mx + c
m is the slope of the graph and c is the y-intercept
In this case, m = 5 as stated in the question, so...
y = 5x + c
By substituting the given co-ordinates (-2,-1) into this equation, we can find c
-1 = 5(-2) + c
-1 = -10 + c
-1 + 10 = -10 + c + 10 (Add 10 to both sides)
9 = c
c = 9
Put c = 9 into the equation:
y = 5x + 9
Answer:
-2
Step-by-step explanation:
1) Look at the y-intercept. The line crosses the y-axis at (0,7)
Follow it down, it goes down two and over one to directly intersect the grid.
Rise over run = 2/1
2/1 = 2
However, the line is negative, as it's sloping down from the left to the right, making the slope -2
Answer:
I'd say none, as we're missing something in this problem. Make sure you've included everything to solve this problem. Thanks.
