Answer:
Both A and B are true identities
Step-by-step explanation:
A. N ( n − 2 ) ( n + 2 ) = n 3 − 4 n
We need to show that (left-hand-side)L.H.S = R.H.S (right-hand-side)
So,
n ( n − 2 ) ( n + 2 ) = n(n² - 2²) (difference of two squares)
= n³ - 2²n (expanding the brackets)
= n³ - 4n (simplifying)
So, L.H.S = R.H.S
B. ( x + 1 )² − 2x + y² = x² + y² + 1
We need to show that (left-hand-side)L.H.S = R.H.S (right-hand-side)
So,
( x + 1 )² − 2x + y² = x² + 2x + 1 - 2x + y² (expanding the brackets)
= x² + 2x - 2x + 1 + y² (collecting like terms)
= x² + 1 + y²
= x² + y² + 1 (re-arranging)
So, L.H.S = R.H.S
So, both A and B are true identities since we have been able to show that L.H.S = R.H.S in both situations.
I could be wrong but I think 28.
Always, ALWAYS remeber this format: y = mx + b
In this equation, 'm' is the slope, and 'b' is the y-intercept
When you're trying to find a slope, remember that the equation is 
When finding the rise and run, look at two points that are on the graph AND on the line as well. Essentially, make sure the points you're using are integers.
In this, case, the rise is -3, and the run is 2. This means that the slope is 
Now we have the first part of our equation:
y = -
+ b
But wait! How do we find b?
Sometimes you have to input x in order to find it, but only when you're not supplied with a graph. In this case, all you have to do is look!
The point of the line that is on the y-axis is called the y-intercept.
In this graph, the y-intercept is -1
Now we have our complete equation!
y = -
- 1
Good luck!