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
Answer:
Perimeter units. Area 12 square units.
Step-by-step explanation:
Perimeter: total distance around the figure.
Distance Formula: the distance between points is
The perimeter is the sum of all those segment lengths.
One way to find the area of the figure is to surround it with a rectangle, insert some lines so that the areas you do not want can be found and subtracted from the rectangle's area. (See attached image.)
The area of the large rectangle around the figure is 5 x 4 = 20 square units.
The triangles have areas 1/2 (base) (height):
A. (1/2)(1)(4) = 2 square units
B. (1/2)(3)(1) = 1.5 square units
D. (1/2)(1)(2) = 1 square unit
E. (1/2)(5)(1) = 2.5 square units
Square C. (1)(1) = 1 square unit
Total of all the area you don't want to include:
2 + 1.5 + 1 + 2.5 + 1 = 8 square units
Subtract 8 from the surrounding rectangle's area of 20, and you get the area of the figure is 20 - 8 = 12 square units.
