The first equation, 8x - 9y = - 23
Obtain the equation in slope- intercept form
y = mx + c ( m is the slope and c the y-intercept )
to calculate m use the gradient formula
m = ( y₂ - y₁ ) / ( x₂ - x₁ )
with (x₁, y₁ ) = ( 
, 3) and (x₂, y₂ ) = (- 4, - 1 )
m = 
= (- 4)/- 
= 
partial equation is y = x + c
to find c substitute either of the 2 points into the partial equation
using (- 4, - 1 ), then
- 1 = - 
+ c ⇒ c = 
y = x + ← in slope- intercept form
the equation of a line in standard form is
Ax + By = C ( A is a positive integer and B, C are integers )
rearrange the slope- intercept equation into this form
multiply through by 9
9y = 8x + 23 ( subtract 9y and 23 from both sides )
8x - 9y = - 23 in standard form
Recall that the diagonals of a rectangle bisect each other and are congruent, therefore:
Substituting the given expression for each segment in the first equation, we get:
Solving the above equation for x, we get:
Substituting x=10 in the equation for segment EI, we get:
Therefore:
Now, to determine the measure of angle IEH, we notice that:
therefore,
Using the facts that the triangles are right triangles and that the interior angles of a triangle add up to 180° we get:
<h2>Answer: </h2>
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Answer: 
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Given: 
Find: 
Solution: In order to determine if (1, 1) is a solution we need to plug in 1 for the x values and 1 for the y values and see if the equation evaluated to true.
<u>Plug in the values</u>
<u>Simplify</u>
As we can see the expression states that 1 is less than or equal to -2 which is false therefore (1, 1) is NOT a solution of the inequality.
11/18 =0.6111111. I don’t think the ! Has any meaning
Depends on what the measurement is.
