The key is to work from the middle.
c - (d - e) - f = c - d + e - f
b - (c - d + e - f) - g = b - c + d - e + f - g
a - (b - c + d - e + f - g) = a - b + c - d + e - f + g
Answer:
a - b + c - d + e - f + g
This is a difference of perfect squares which is of the form:
(a^2-b^2)
And which always factors to:
(a-b)(a+b)
In this case:
(5x-8)(5x+8)
For points (x1,y1) and (x2,y2)
the slope is (y2-y1)/(x2-x1)
(3,4) and (6,6), slope is (6-4)/(6-3)=2/3
(4,-4) and (2,-7), slope is (-7-(-4))/(2-4)=(-7+4)/(-2)=-3/-2=3/2
for ax+by=c
slope=-a/b
3x+4y=12
slope=-3/4
Given:
The set of ordered pairs in the options.
To find:
The set of ordered pairs which does not represent a function.
Solution:
A set of ordered pairs represents a function if their exist a unique y-value for each x-value.
In option 3, the given set of ordered pair is:
{(−3,−3),(4,1),(−3,3),(2,2)}
Here, we have to y-values -3 and 3 for x=-3. It means the y-value is not unique for x=-3. So, this set of ordered pairs is not a function.
In option 1, 2 and 4, all the x-coordinates are different. It means their exist a unique y-value for each x-value. So, the set of ordered pairs in options 1, 2 and 4 represent a function.
Therefore, the correct opting is 3.
The answer is 3, just do 20*0.15 (covert 15% into a decimal).