The answer is A
Have to add characters to get to 20
Complete Question: Which of the following is an example of the difference of two squares?
A x² − 9
B x³ − 9
C (x + 9)²
D (x − 9)²
Answer:
A.
.
Step-by-step explanation:
An easy way to spot an expression that is a difference of two squares is to note that the first term and the second term in the expression are both perfect squares. Both terms usually have the negative sign between them.
Thus, difference of two squares takes the following form:
.
a² and b² are perfect squares. Expanding
will give us
.
Therefore, an example of the difference of two squares, from the given options, is
.
can be factorised as
.
What you want to do is cross multiply so you get 5(x+4)=7(3x+28) then you distrubute the 5 and then you distribute the 5 and the 7 to the number in the parentheses 5x+20=21x+196
subtract 5x on both sides to get 20=16x+196 then you subtract 196 on both sides to get -176=16x last what you want to do is divide 16 on both sides to get x=-11
Slope is also known as rise over run -

Here, we have the slope

. This means that the rise is

and the run is

. Since both values are positive, we can say that we go up one and we go right four. When we plot this on a graph (the graph is attached), we get the same exact formula we found. **In the graph, I plotted the line

**. Hope this helped!