<span>Answer:
The multiplication factor of increase should be inverse of the multiplication factor of decrease.
e.g. Say you have a number 100.
You increase it by 25%. The multiplication factor is 5/4 i.e. when you multiply 100 by 5/4, you get 100*5/4 = 125. This is 25% more than 100.
Now you want to decrease it by a certain % such that you get 100 back.
Basically, 100*5/4 * x = 100
So x = 4/5 (inverse of 5/4)
Hence, you decrease by 20% (the multiplication factor of 20% is 4/5)
or
Use this formula: cumulative % change = a + b + ab/100
You want the cumulative change to be 0.
a + b + ab/100 = 0
If you know that you are increasing by 25% and want to find the % by which you should decrease to get the same number,
25 + b + 25b/100 = 0
5b/4 = -25
b = -20
So you need to decrease (hence you get the -ve sign) by 20%.</span>
Answer:
1. makes two right triangles
2. not similar
3. similar, the bottom one is dilated by 3
Answer:
I'm going to do 1 as an example and using what I've taught you, you have to do the rest. Hope my explanation helps.
Step-by-step explanation:
We are given the points (-2, -4) and (-1, -1)
We need to find the slope.
The equation to do so is y2 - y1 / x2 - x1
lest say:
-2 is x1
-4 is y1
-1 is x2
-1 is y2
-1 - (-4) / -1 - (-2)
3/1 = 3
slope (m) = 3
We already know the y-intercept is 2
The equation of a line is y = mx + b
For this problem we just have to substitute what we already know.
y = (slope)x + y-intercept
y = 3x + 2
*TIP*
If the y-intercept is negative, let's say: b = -5 (using slope 8)
the equation will be y = 8x - 5
Hope this helps. I wish you all the best. :)
